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Rumanite

A synonym

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Opal

South Wollo Zone, Amhara Region, Ethiopia

Opal-CT, etc.

Pont-du-Château, Clermont-Ferrand, Puy-de-Dôme, Auvergne-Rhône-Alpes, France

Opal

Bohouškovice opal occurrences, Bohouškovice, Kremze, Český Krumlov District, South Bohemian Region, Czech Republic

Opal

South Wollo Zone, Amhara Region, Ethiopia

Opal-CT, etc.

Pont-du-Château, Clermont-Ferrand, Puy-de-Dôme, Auvergne-Rhône-Alpes, France

Opal

Bohouškovice opal occurrences, Bohouškovice, Kremze, Český Krumlov District, South Bohemian Region, Czech Republic

Opal

South Wollo Zone, Amhara Region, Ethiopia

Opal-CT, etc.

Pont-du-Château, Clermont-Ferrand, Puy-de-Dôme, Auvergne-Rhône-Alpes, France

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About RumaniteHide

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Synonym of:

Amber, Opal

Opal or Amber from Romania

Unique IdentifiersHide

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Mindat ID:

9825

Long-form identifier:

mindat:1:1:9825:6

GUID
(UUID V4):

29fdd77b-444e-4260-80f0-2e9ce517b92f

Other InformationHide

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Health Risks:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Rumanite in petrologyHide

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References for RumaniteHide

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Reference List:

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Neacşu, A. (2006) Remarks on The Geological Origin of Rumanite. Acta Mineralogica-Petrographica, Abstract Series 5, Szeged. p 83

Internet Links for RumaniteHide

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mindat.org URL:

https://www.mindat.org/min-9825.html
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Localities for RumaniteHide

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This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the

symbol to view information about a locality. The

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Locality ListShow

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- This locality has map coordinates listed.

- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality.

- Good crystals or important locality for species.

- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). ~~Struck out~~ - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.


Afghanistan
Badakhshan Zebak District Sanglich ⓘ Alburs	[Opal] Orris, G.J., and Bliss, J.D. (2002): Mines and Mineral Occurrences of Afghanistan. United States Geological Survey Open-File Report 02-110
Balkh Chimtal District ⓘ Alburs sulphur deposit	[Opal] Orris, G.J., and Bliss, J.D. (2002): Mines and Mineral Occurrences of Afghanistan. United States Geological Survey Open-File Report 02-110
Nuristan Kamdesh District ⓘ Paprok	[Opal] Jose Zendrera collection

Algeria
Mostaganem Province Sidi Lakhdar District Sidi Lakhdar ⓘ Kieselguhr Quarry	[Opal] Rocks & Min.: 17:243.

Angola
Luanda Province ⓘ Belas	[Opal] Martins da Pedra collection

Anguilla	[Amber] Earle, K. W. (1922). Reports on the Geology of St. Kitts-Nevis, BWI, and the Geology of Anguilla, BWI. Crown Agents for the Colonies.

ⓘ Crocus Bay Beach	[Amber] Earle, K. W. (1922). Reports on the Geology of St. Kitts-Nevis, BWI, and the Geology of Anguilla, BWI. Crown Agents for the Colonies.

Antarctica
Eastern Antarctica Victoria Land Elephant Moraine ⓘ Elephant Moraine 83309 meteorite	[Opal] Beard, A. D., Downes, H. & Howard, K. (2009) Hydrated Silica (Opal) in a Polymict Ureilite, EET 83309: Meteoritics & Planetary Science 44 (7, Supplement): page. A31. (Sept 2009).
ⓘ Mount Adamson	[Opal] Galli E, Vezzalini G, Quartieri S, Alberti A, Franzini M (1997) Mutinaite, a new zeolite from Antarctica: the natural counterpart of ZSM-5, Zeolites 19, 318-322
ⓘ Mt Melbourne	[Opal] Collection of RJ Martin
Ross Archipelago Ross Island ⓘ Mount Erebus	[Opal] Collection of RJ Martin
Western Antarctica Antarctic Peninsula Bransfield Strait ⓘ Hook Ridge	[Opal] Petersen et al. (2004) Hydrothermal precipitates associated with bimodal volcanism in the Central Bransfield Strait, Antarctica. Mineralium Deposita 39: 358-379, DOI 10.1007/s00126-004-0414-3

Arctic Ocean
ⓘ Kara Sea	[Opal] Bogdanov, Y. A., Gurvich, E. G., Bogdanova, O. Y., Ivanov, G. V., Isaeva, A. B., Muravév, K. G., ... & Dubinina, G. I. (1995). Ferromanganese nodules of the Kara Sea. Oceanology, English Translation, VOL. 34, NO. 5, A pp 722-732

Argentina
Catamarca Province Ambato Department Los Varela ⓘ Estancia Cóndor Huasi	[Opal] Raúl Jorge Tauber Larry (1971). Informe personal de la visita a la Estancia "´Cóndor Huasi" en Las Estancias Departamento Andalgalá, Provincia de Catamarca, Argentina.
Andalgalá Department Aconquija ⓘ Campo del Pucará	[Opal] Raúl Jorge Tauber Larry photo and collection
ⓘ Capillitas mining district	[Opal] Raúl Jorge Tauber Larry
Antofagasta de la Sierra Department ⓘ Campos de Piedra Pómez	[Opal] Tauber, Sebastian (2016) unpublished data on site visit.
Belén Department Corral Quemado ⓘ Papachacra	[Opal-A var: Opal-AN] Padrón de Minas de la Provincia de Catamarca.
Sierra de Ancasti El Portezuelo ⓘ El Portezuelo Granite	[Opal] Colombo, F., Lira, R., Simmons, W., & Falster, A. (2011). The NYF-type miarolitic-rare earth elements pegmatites of the El Portezuelo granite, Papachacra (Catamarca, NW Argentina). Asoc. Geol. Arg., Serie D, Publicación Especial, 14, 57-59.
Chubut Province Cushamen Department ⓘ El Mirador	[Opal] Padrón de Minas de la Provincia de Chubut (2005).
Gastre Department ⓘ El Escorial	[Opal] Padrón de Minas de la Provincia de Chubut (2005).
Languiñeo Department Piedra Parada ⓘ Piedra Parada caldera	[Opal] ARAGON, E. et al. Petrogenesis of thundereggs in Eocene rhyolite domes of central Chubut, Patagonia. Rev. Asoc. Geol. Argent. [online]. 2006, vol.61, n.3, pp. 347-354.
ⓘ Pocitos de Quichaura	[Opal-A var: Opal-AN] Padrón de Minas de la Provincia de Chubut (2005).
Paso de Indios department El Sombrero Sierra Cuadrada deposit ⓘ Lagartija occurrence	[Opal] Raúl Jorge Tauber Larry C. T. Friz, F. Rodrigo y P.N. Stipanicic - Recursos y posibilidades Uraníferas en Argentina. Session 2.11 P/405. Comision Nacional de Energia Atomica. Victorio Angelelli (1958) Los minerales de Uranio sus yacimientos y prospección. Departamento de Geología y Minería. Comision Nacional de Energia Atomica.
Telsen Department ⓘ Gan Gan	[Opal] Padrón de Minas de la Provincia de Chubut (2005).
Córdoba Province Punilla Department San Roque District Tanti Cerro Blanco pegmatite district ⓘ El Criollo Mine	[Opal] Alfredo Petrov field collected specimens, April 1993.
San Alberto Department Tránsito District Mina Clavero ⓘ Rio de los Sauces	[Opal] C. Lemanski, Jr. (re-entry of lost Mindat data).
Sobremonte Department Aguada Del Monte District ⓘ El Portezuelo district	[Opal] LEAL, Pablo Rodrigo and GONZALEZ, María Paz. Mineralogy and fluid inclusion of LaBaritina: theuppermost sector of the manganese mineralization of sierra de Ambargasta, province of Córdoba. Rev. Asoc. Geol. Argent. [online]. 2009, vol.64, n.4, pp. 672-684
Entre Ríos Province ⓘ Colón Department	[Opal] Juan Carlos Lodovichi
Cuarto District ⓘ El Palmar National Park	[Opal] Zucol, A. F., Brea, M., & Scopel, A. (2005). First record of fossil wood and phytolith assemblages of the Late Pleistocene in El Palmar National Park (Argentina). Journal of South American Earth Sciences, 20(1-2), 33-43.
ⓘ Paraná Department	[Opal] Raúl Jorge Tauber Larry (1967). Visita al arroyo Espinillo en la Provincia de Entre Ríos.
ⓘ Arroyo Espinillo	[Opal] Raúl Jorge Tauber Larry (1967). Visita al arroyo Espinillo en la Provincia de Entre Ríos.
Jujuy Province Cochinoca Department Abra Pampa ⓘ Rachaite	[Opal] Coira, B. L., & de Brodtkorb, M. K. (1995) Polymetallic mineralization associated with Cenozoic volcanism in Northern Puna, Argentina. In Pacrim (Vol. 95, pp. 135-140).
ⓘ Rachaite prospect	[Opal] Milka K. de Brodtkorb (2002) Las Especies Minerales de la Republica Argentina. Vol. 1 (elements, sulphides and sulphosalts). (Asociacion Mineralogica Argentina)
La Rioja Province Coronel Felipe Varela department Guandacol ⓘ Cerro Bola	[Opal] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
ⓘ Talampaya National Park	[Opal] Ra{ul J. Tauber Larry
Mendoza Province Malargüe Department Agua Escondida District Altiplano de Payún Matrú ⓘ Payún Matrú volcano	[Opal-A var: Opal-AN] Alfredo Petrov collection
San Rafael Department Cuadro Benegas District ⓘ Lomas Bayas	[Opal] Aguirre-Urreta, M. B.(1), Rawson, P. F.(2), Concheyro, G. A.(1), Bown, P. R.(2) & Ottone, E. G.(1).
Neuquén Province ⓘ Catán Lil Department	[Opal] Montagne, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
ⓘ Bajada de Los Molles	[Opal] Tauber, S. (November 2014)
ⓘ Morro del Águila	[Opal] Tauber, S.
Collón Curá Department Piedra del Águila ⓘ Cerro Mesa	[Opal] Mirta Quattrocchio(1), Marcelo Martínez(1,2), Vivian García1 y Carlos Zavala(1). BIOEVENTO DEL VALANGINIANO TARDÍO EN EL CENTRO-OESTE DE LA CUENCA NEUQUINA.
Loncopué Department ⓘ Agua de La Mula	[Opal] Aguirre-Urreta, M. B.(1), Rawson, P. F.(2), Concheyro, G. A.(1), Bown, P. R.(2) & Ottone, E. G.(1)
ⓘ Caverna de Chorriaca	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Caverna de Huitrín	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Caverna del Salado I	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Caverna del Salado II	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Caverna del Salado III	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Portal de Los Monos	[Opal] Montagne, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
Ñorquín Department ⓘ Arroyo Truquicó	[Opal] Darío G. Lazo, Leticia Luci. Revision of Valanginian Steinmanellinae bivalves from the Neuquén
ⓘ Caverna de Reni	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
Pehuenches Department ⓘ Loma La Torre	[Opal] Montagna, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Guía Práctica. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
ⓘ Puerta Curaco	[Opal] Montagna, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Guía Práctica. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
ⓘ Picunches Department	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Bajada del Agrio	[Opal] Montagna, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Guía Práctica. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
ⓘ Bajada Vieja	[Opal] Montagna, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Guía Práctica. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
ⓘ Caverna del León	[Opal] Silvia Barredo (1), Norberto Gabriele (2), Alberto Garrido (3) y Gabriel Redonte (4). "Los principales sistemas de cavernas cársticas de la provincia del Neuquén".(1) Instituto Tecnológico de Buenos Aires (ITBA), Instituto del Gas y Petróleo (UBA). Grupo Espeleológico Argentino (GEA). E-mail: sbarredo@itba.edu.ar (2) Universidad Nacional del Centro, Facultad de Ciencias Exactas. Centro de Montaña Tandil (CMT) Municipalidad de Tandil. E-mail: gabriele@exa.unicen.edu.ar (3) Museo Provincial de Ciencias Naturales "Prof. Dr. Juan A. Olsacher" - Dirección Provincial de Minería. Zapala, Neuquén. E-mail: algene@copelnet.com.ar (4) Grupo Espeleológico Argentino (GEA). E-mail: gabriel.redonte@gea.org.ar
ⓘ Sierra de la Vaca Muerta	[Opal] Tauber, S. (2014). Visita a la zona, Noviembre de 2014.
ⓘ Zapala Department	[Opal] Montagne, A. O., Ponce, J. J. y Buhler, M. (2014). Geología de la cuenca Neuquina y sus sistemas petroleros. Fundación YPF-Universidad Nacional de Río Negro, Argentina.
Río Negro Province Veinticinco de Mayo Department ⓘ Cruz del Sur mine	[Opal] American Mineralogist (1978) 63, 1175-1181
ⓘ Salar del Hombre Muerto	[Opal] Raúl J. Tauber Larry
Salta Province La Poma Department ⓘ Diana Mine	[Opal] A. G. Quiroga y T. Ruíz (1994). Mimetesita, Pb5[Cl(AsO4)3] de la mina Diana, dpto. La Poma, provincia de Salta, Argentina. 2da Reunión de Mineralogía y Metalogenia. Instituto Nacional de Recursos Mineros, UNLP. Publicación 3:325-335.
Los Andes department San Antonio de los Cobres ⓘ Taron Project	[Opal] Ronald G. Simpson (2017) Taron Project NI 43-101 Technical Report Salta Province, Argentina Trueman, D., Downing, B., Ledoux, T., Richards, T. (2020): The Taron cesium–thallium epithermal geyserite deposit, Salta Province, Argentina. EXPLORE 188, 13-19.
San Juan Province Calingasta Department Calingasta ⓘ San Francisco de los Andes mine	[Opal] Zubía, M. A., Giacosa, R. E., Godeas, M. C., Segal, S. J., Korzeniewski, L. I., Cardó, R., ... & Chernicoff, C. J. (2008). Estudio Metalogenético de Brechas Hidrotermales Portadoras de Mineralización de Bi-Au-Cu en el Ámbito de la Cordillera Frontal. Provincia de San Juan/Modelo de Mineralización en" El Pingüino"(Depósito Cerro León), Región del Deseado, Santa Cruz. Instituto DE Geología Y Recursos Minerales Servicio Minero Argentino Secretaría DE Minería DE LA Nación. Serie Contribuciones Técnicas - Recursos Minerales Nº 31
Valle Fértil Department ⓘ Parque Provincial Reserva Natural Valle de la Luna	[Opal] Raúl J. Tauber Larry
San Luis Province Coronel Pringles Department El Trapiche La Florida ⓘ San Luis Mine	[Opal] Galliski, M. A., Márquez-Zavalía, M. F., Martínez, V., & Roquet, M. B. (2011). Granitic pegmatites of the San Luis ranges. In 5th International Symposium on Granitic Pegmatites, PEG2011 Argentina, Field Trip Guidebook: Ianigla-Conicet (Vol. 44, pp. 873-894).
ⓘ San Luis II pegmatite	[Opal] Černý, P., Galliski, M. A., Oyarzábal, J. C., Teertstra, D. K., Chapman, R., MacBride, L., & Ferreira, K. (2003). Stranded and equilibrated assemblages of late feldspars in two granitic pegmatites in the Pampean Ranges, Argentina. The Canadian Mineralogist, 41(4), 1013-1026.; Galliski, M. A., Márquez-Zavalía, M. F., Martínez, V., & Roquet, M. B. (2011). Granitic pegmatites of the San Luis ranges. In 5th International Symposium on Granitic Pegmatites, PEG2011 Argentina, Field Trip Guidebook: Ianigla-Conicet (Vol. 44, pp. 873-894).
San Martín Department ⓘ María Elena pegmatite	[Opal] Galliski, M. A., Márquez-Zavalía, M. F., & Roquet, M. B. (2009). The Nb-Ta-U oxide minerals from María Elena Pegmatite, San Luis, Argentina. Estudos Geológicos, 19(2), 127.
Santa Cruz Province Deseado Department ⓘ Monumento Natural Bosques Petrificados	[Opal] Raúl Jorge Tauber Larry
ⓘ Cerro Madre e Hija	[Opal] Aliotta, G., Garrido, M., Gómez, C y Luna, L. 1996. Estudio de zeolitas de la zona de “Madre e Hija” (Santa Cruz). 3ª Reunión de Mineralogía y Metalogenia. Instituto de Recursos Minerales, UNLP. Publicación 5: 9-16.
Tres Cerros ⓘ La Josefina prospect	[Opal] Moreira, P., & Fernández, R. R. (2015). La Josefina Au–Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment. Ore Geology Reviews, 67, 297-313.
ⓘ San Pedro-La Evelina deposit	[Opal] DEL BLANCO, Miguel et al. Characteristicsof a shallow epithermal mineralization in the Deseado Massif, Patagonia. Rev. Asoc. Geol. Argent. [online]. 2009, vol.64, n.3, pp. 373-382.
Lago Buenos Aires Department Sascha Project ⓘ Pelligrini prospect	[Opal] Smith, Q. E. (2009). Volcanic stratigraphy, alteration zoning, and vein paragenesis of the Sascha-Pelligrini low-sulphidation epithermal system, Santa Cruz, Argentina (Doctoral dissertation, Queensland University of Technology).
Santiago del Estero Province Ojo de Agua Department ⓘ Cantamampa vein	[Opal] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
ⓘ Ojo de Agua vein	[Opal] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
ⓘ Ojo de Agua Veta Sur	[Opal] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
Piedras Blancas ⓘ Piedras Blancas pegmatite	[Opal-A var: Opal-AN] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
Quebrachos Department Sumampa Sumampa Viejo ⓘ Sumampa Viejo vein	[Opal] LEAL, P.R.; CORTONA, O. y PAGAN, F.J.. Vetas de cuarzo en el sur de Santiago del Estero. Rev. Asoc. Geol. Argent. [online]. 2005, vol.60, n.2, pp. 389-401
ⓘ Tucumán Province	[Opal] Raúl Jorge Tauber Larry; Hugo A. Peña (1970): Minerales y rocas de aplicación de la Provincia de Tucumán. Secretaría de Estado de Comercio, Industria y Minería. Dirección Provincial de Minas. Tucumán. República Argentina.
ⓘ Chicligasta Department	[Opal] Sub secretaría de Minerái de la Nación (1974). Reporte técnico. Argentina.
Alpachiri y El Molino Parque Nacional Campo de los Alisos ⓘ Río Jaya	[Opal] Collected by Sebastián Tauber, November 2016
La Cocha Department El Sacrificio Cerro Quico ⓘ Piedras Blancas deposit	[Opal] Raúl Jorge Tauber Larry
ⓘ Tafí del Valle Department	[Opal] Raúl Jorge Tauber Larry
Amaicha del Valle ⓘ Los Zazos	[Opal] Raúl Jorge Tauber Larry
ⓘ Tío Punco	[Opal] Raúl Jorge Tauber Larry

Armenia
Kotayk Province Hrazdan ⓘ Hrazdan Iron-Ore project	[Opal] Bowell, Rob, Christopher Brough, Andrew Barnes, and Arman Vardanyan. (2021) "Geometallurgy of Trace Elements in the Hrazdan Iron Deposit" Minerals 11, no. 10: 1085. https://doi.org/10.3390/min11101085

Atlantic Ocean
Mid-Atlantic Ridge complex ⓘ Ashadze hydrothermal area	[Opal] Cherkashev, G. A., Ivanov, V. N., Bel’Tenev, V. I., Lazareva, L. I., Rozhdestvenskaya, I. I., Samovarov, M. L., ... & Kuznetsov, V. Y. (2013). Massive sulfide ores of the northern equatorial Mid-Atlantic Ridge. Oceanology, 53(5), 607-619.
ⓘ Irinovskoe hydrothermal field	[Opal] Melekestseva, Irina, Vasiliy Kotlyarov, Gennadiy Tret’yakov, Vladimir Shilovskikh, Pavel Khvorov, Elena Belogub, Victor Beltenev, Kseniya Filippova, and Sergey Sadykov. 2022. "The Heavy-Metal Fingerprint of the Irinovskoe Hydrothermal Sulfide Field, 13°20′ N, Mid-Atlantic Ridge" Minerals 12, no. 12: 1626. https://doi.org/10.3390/min12121626
ⓘ Koralovoe hydrothermal area	[Opal] Sudarikov, Sergei, Egor Narkevsky, and Vladimir Petrov. (2021) "Identification of Two New Hydrothermal Fields and Sulfide Deposits on the Mid-Atlantic Ridge as a Result of the Combined Use of Exploration Methods: Methane Detection, Water Column Chemistry, Ore Sample Analysis, and Camera Surveys" Minerals 11, no. 7: 726. https://doi.org/10.3390/min11070726
ⓘ Krasnov hydrothermal field	[Opal] Mozgova, N. N., Borodaev, Y. S., Gablina, I. F., Stepanova, T. V., Cherkashev, G. A., & Uspenskaya, T. Y. Y. (2007). Features of transformation of the mineral paragenetic assemblages from copper sulfide ores of the Krasnov hydrothermal field (16° 38'N Mid Atlantic Ridge). New Data on Minerals, 62.
ⓘ Molodezhnoe hydrothermal area	[Opal] Sudarikov, Sergei, Egor Narkevsky, and Vladimir Petrov. (2021) "Identification of Two New Hydrothermal Fields and Sulfide Deposits on the Mid-Atlantic Ridge as a Result of the Combined Use of Exploration Methods: Methane Detection, Water Column Chemistry, Ore Sample Analysis, and Camera Surveys" Minerals 11, no. 7: 726. https://doi.org/10.3390/min11070726
ⓘ Petersburgskoe hydrothermal field	[Opal] Gablina, I. F., Dobretsova, I. G., Narkevskii, E. V., Gustaitis, A. N., Sadchikova, T. A., Gor’kova, N. V., ... & Dara, O. M. (2017). Influence of hydrothermal-metasomatic processes on the formation of present-day sulfide ores in carbonate bottom sediments of the Mid-Atlantic Ridge (19°–20° N). Lithology and Mineral Resources, 52, 335-357.
ⓘ Pobeda-1 hydrothermal field	[Opal] Gablina, I. F., Dobretzova, I. G., Laiba, A. A., Narkevsky, E. V., Maksimov, F. E., & Kuznetsov, V. Y. (2018). Specific Features of Sulfide Ores in the Pobeda Hydrothermal Cluster, Mid-Atlantic Rise 17° 07′–17° 08′ N. Lithology and Mineral Resources, 53(6), 431-454. Maslennikov, Valeriy V., Georgy A. Cherkashov, Anna V. Firstova, Nuriya R. Ayupova, Victor E. Beltenev, Irina Yu. Melekestseva, Dmitry A. Artemyev, Aleksandr S. Tseluyko, and Ivan A. Blinov. (2023) "Trace Element Assemblages of Pseudomorphic Iron Oxyhydroxides of the Pobeda-1 Hydrothermal Field, 17°08.7′ N, Mid-Atlantic Ridge: The Development of a Halmyrolysis Model from LA-ICP-MS Data" Minerals 13, no. 1: 4. https://doi.org/10.3390/min13010004
ⓘ Pobeda-2 hydrothermal field	[Opal] Gablina, I. F., Dobretzova, I. G., Laiba, A. A., Narkevsky, E. V., Maksimov, F. E., & Kuznetsov, V. Y. (2018). Specific Features of Sulfide Ores in the Pobeda Hydrothermal Cluster, Mid-Atlantic Rise 17° 07′–17° 08′ N. Lithology and Mineral Resources, 53(6), 431-454.
Rainbow Massif ⓘ Rainbow hydrothermal field	[Opal] Bortnikov, N. S., Vikentyev, I. V., Apollonov, V. N., Stavrova, O. O., Bogdanov, Y. A., Lein, A. Y., ... & Ikorskii, S. V. (2001). The Rainbow serpentinite-related hydrothermal field, Mid-Atlantic Ridge, 36 14′ N: mineralogical and geochemical features. In Proc. Joint Sixth Meeting. Mineral Deposits at the Beginning of the 21st Century, Krakow, 26–29 August (pp. 265-268).
ⓘ Semenov region	[Opal] Melekestseva, I. Y., Tret'yakov, G. A., Nimis, P., Yuminov, A. M., Maslennikov, V. V., Maslennikova, S. P., ... & Large, R. (2014). Barite-rich massive sulfides from the Semenov-1 hydrothermal field (Mid-Atlantic Ridge, 13° 30.87′ N): Evidence for phase separation and magmatic input. Marine Geology, 349, 37-54.
ⓘ Semyenov-1 Hydrothermal Field	[Opal] Safina, N. P., Melekestseva, I. Y., Nimis, P., Ankusheva, N. N., Yuminov, A. M., Kotlyarov, V. A., & Sadykov, S. A. (2016). Barite from the Saf’yanovka VMS deposit (Central Urals) and Semenov-1 and Semenov-3 hydrothermal sulfide fields (Mid-Atlantic Ridge): a comparative analysis of formation conditions. Mineralium Deposita, 51(4), 491-507.
ⓘ Semyenov-2 Hydrothermal Field	[Opal] Firstova, A., Stepanova, T., Sukhanova, A., Cherkashov, G., & Poroshina, I. (2019). Au and Te Minerals in Seafloor Massive Sulphides from Semyenov-2 Hydrothermal Field, Mid-Atlantic Ridge. Minerals, 9(5), 294.
Sierra Leone fracture zone Markov Deep ⓘ Northeastern rim	[Opal] Sharkov, E.V., Abramov, S.S., Simonov, V.A., Krinov, D.I., Skolotnev, S.G., Bel’tenev, V.E., and Bortnikov, N.S. (2007): Geology of Ore Deposits 49(6), 467-486.
ⓘ Snake Pit hydrothermal field	[Opal] S. M. Sudarikov and S. V. Galkin Geochemistry of the Snake Pit vent field and its implications for vent and non-vent fauna Geological Society, London, Special Publications 1995, 87:319-327; Fouquet, Y., Wafik, A., Cambon, P., Mevel, C., Meyer, G., & Gente, P. (1993). Tectonic setting and mineralogical and geochemical zonation in the Snake Pit sulfide deposit (Mid-Atlantic Ridge at 23 degrees N). Economic geology, 88(8), 2018-2036.
ⓘ Moose Mound	[Opal] Fouquet Y, Wafik A, Cambon P, Mevel C, Meyer G, Gente P(1993) Tectonic setting and mineralogical and geochemical zonation in the Snake Pit sulfide deposit (Mid-Atlantic Ridge at23°N). Econ Geol Bull Soc Econ Geol 88:2018–2036
Trans-Atlantic Geotraverse hydrothermal field (TAG) ⓘ TAG mound	[Opal] Petersen, S., Herzig, P.M., and Hannington, M.D. (2000): Mineralium Deposita 35, 233-259.
ⓘ Zenith–Victoria hydrothermal field	[Opal] Gablina, I. F., Dobretsova, I. G., Narkevskii, E. V., Gustaitis, A. N., Sadchikova, T. A., Gor’kova, N. V., ... & Dara, O. M. (2017). Influence of hydrothermal-metasomatic processes on the formation of present-day sulfide ores in carbonate bottom sediments of the Mid-Atlantic Ridge (19°–20° N). Lithology and Mineral Resources, 52, 335-357.
Southern Mid-Atlantic Ridge complex 26°S hydrothermal field ⓘ Xunmei hydrothermal site	[Opal] Yang, B., Liu, J., Li, C., Zhu, A., Wang, H., Cui, J., ... & Shi, X. (2022). Mineralogical and geochemical characteristics of near-vent metalliferous sediments: Implications for hydrothermal processes along the southern Mid-Atlantic ridge (12° S–28° S). Ore Geology Reviews, 148, 105003.

Australia
Australian Capital Territory Paddy's River District ⓘ Paddy's River Mine	[Opal-A var: Opal-AN] McQueen, Ken G.; J. R. Caldwell; P. W. Millsteed (July 1988). "Primary and Secondary Minerals at the Paddy's River Mine, Australian Capital Territory". Australian Mineralogist 3: 83–100.
New South Wales Bathurst Co. Carcoar ⓘ Carcoar Mine (Carcoar cobalt mine; Wilsons mine; Wilsons quarry)	[Opal] Liversidge 1887, Minerals of New South Wales
Beresford Co. Snowy Mts district ⓘ Cooma metamorphic Complex	[Opal] John Whitehouse (2015) Geologic Evolution of Miocene Diatomite Occurrences, New South Wales, Australia
Brisbane Co. ⓘ Bunnan	[Opal-A var: Opal-AN] Collection of RJ Martin correlated to similar exposures
Buccleuch Co. Coolac district ⓘ Mount Mary Mine	[Opal-A var: Opal-AN] Minerals in podiform chromitites - Tumut Serpentinite Province, Southern New South Wales, Graham, Franklin and Marshall, 2001, Australian Journal of Mineralogy 7(1).
Burnett Co. ⓘ Mount Cora	[Opal-A var: Opal-AN] Curtis, N.J., Gascooke, J.R., Johnston, M.R., Pring, A. (2020) A Review of the Classification of Opal with Reference to Recent New Localities. Minerals 2019, 9, 299.
Camden Co. ⓘ Bundanoon	[Opal] Wray, R.A.L. (2001): Alunite formation within silica stalactites from the Sydney Region, South-eastern Australia. International Journal of Speleology 40, 109-116.
Canbelego Co. Miandetta ⓘ Lynch and party (Miandetta deposit)	[Opal] Gilligan, L.B., Byrnes, J.G. (1995) Metallogenic Study and Mineral Deposit Data Sheets: Cobar Metallogenic Map 1:250 000 (SH/55-14), Geological Survey of New South Wales, Sydney, 240 pages.
Cumberland Co. Prospect ⓘ Prospect Quarry	[Opal] Tschernich, R. (1992): Zeolites of the World, P.48; Min Rec (1994) 25:185-194
Darling Co. Barraba ⓘ Woodsreef Mine (Wood's Reef Mine; Woodsreef Asbestos Mine; Wood'sreef asbestos deposit)	[Opal] Oskierski, H. C., Dlugogorski, B. Z., & Jacobsen, G. (2013) Sequestration of atmospheric CO₂ in chrysotile mine tailings of the Woodsreef Asbestos Mine, Australia: Quantitative mineralogy, isotopic fingerprinting and carbonation rates, Chemical Geology, vol. 358, 156-169.
Finch Co. Collarenebri ⓘ Collarenebri opal field	[Opal]
Cumborah ⓘ Cumborah opal field	[Opal]
ⓘ Lightning Ridge	[Opal] Markham, N.L., Basden, H. (1975) The Mineral Deposits of New South Wales. Department of Mines, Geological Survey of New South Wales, 682 pages. Clifford, J. (et.al.) (2007) Opal - The Phenomenal Gemstone. Mineral Monograph No.10. Lithographie, LLC. East Hampton, Connecticut, USA, 112 pages. Clark, 1993 - "Hey's Mineral Index".
ⓘ Coocoran Opal Fields	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Cheryl's rush (Kellie's 4 rush)	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Cody's rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Dead Bird rush	[Opal] - Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Emu's rush	[Opal] - Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Granny's Flat rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ Greenacres rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ Hard Hill rush	[Opal] - Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville. - Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ K.K. Opal Field	[Opal] aracic
ⓘ Kellie's 1 rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ Ken's Retreat rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Kevin's rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ Molyneux's rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Muttabun (Brown's rush)	[Opal] aracic
ⓘ Natalie's Dream Rush (Natalie's Dream 1)	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ New Coocoran rush	[Opal] Aracic, Stephen (1999), Rediscover Opals in Australia, published 1999 by the Kingswood Press.
ⓘ Norway rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Old Coocoran rush (Coocoran A)	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Olga's rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Ormie's Luck rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Smith's rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Steen's rush (Coocoran C)	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ T-Bone rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003.
ⓘ The Nest rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ The Rocks rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Three Trees rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Glengarry Opal Field	[Opal] aracic; - Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram. - Australian Opal Centre web site http://www.australianopalcentre.com/
ⓘ Grawin Opal Field	[Opal] aracic
ⓘ Three Mile	[Opal]
ⓘ Walk In Mine	[Opal] http://www.walkinmine.com.au/ABOUT.php
ⓘ Wyoming Opal Fields	[Opal] aracic; Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.; Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville
ⓘ Bee Eater rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Francstone 1 rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Francstone 3 rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Great Eastern rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Ironbark rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Les's 8 Mile rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Snake Gully rush	[Opal] Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
ⓘ Wyoming rush	[Opal] Smith, E. & R. (1999): Black Opal Fossils of Lightning Ridge - Treasures from the Rainbow Billabong, Kangaroo Press, East Roseville.
ⓘ Sheepyard Opal Field	[Opal] aracic
Georgiana Co. ⓘ Rocky Bridge Creek	[Opal] W. Curran (1896) Occurrence of precious stones in N.S.W. Journal and Proceedings of the Royal Society of New South Wales, 30, 214-271
Gowen Co. Warrumbungle National Park ⓘ Warrumbungle Volcano	[Opal-A var: Opal-AN] Jensen (1912) Proceedings of the Royal Society of Queensland p186
Macquarie Co. Port Macquarie ⓘ Comboyne Volcanic Province	[Opal]
Narran Co. ⓘ Angledool	[Opal] Caucia, F., Ghisoli, C., Marinoni, L., & Bordoni, V. (2013). Opal, a beautiful gem between myth and reality. Neues Jahrbuch für Mineralogie-Abhandlungen: Journal of Mineralogy and Geochemistry, 190(1), 1-9.
ⓘ Mehi Opal Fields	[Opal] Refs. Cram, L. (2004): A Journey with Colour, Vol 2, Part B - A History of Lightning Ridge Opal 1873-2003, Len Cram.
Mehi ⓘ Mehi Opal Field	[Opal] aracic
Pottinger Co. ⓘ Boggabri	[Opal] Steve Sorrell Collection
ⓘ Mullaley	[Opal-A var: Opal-AN] Specimen in collection
Rous Co. Ballina Shelly Beach ⓘ Black Head (PWD Black Head quarry)	[Opal] Collection of RJ Martin
Teven ⓘ Hitchcocks opal claim ?	[Opal] Warwick–Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps: R.E. Brown, H.F. Henley and W.J. Stroud, December, 2001. Published by the Geological Survey of New South Wales.
ⓘ Houghlahan's Creek opal field	[Opal] Mumme I.A. and Ball R.A. On the Genesis of Volcanic Opal at Houghlahan's Creek Near Teven-Tintenbar, New South Wales, Australian Mineralogist #8 Feb-Mar 1977.
ⓘ Shepherds opal claim	[Opal] Warwick–Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps: R.E. Brown, H.F. Henley and W.J. Stroud, December, 2001. Published by the Geological Survey of New South Wales.
ⓘ Snow Queen Mine (Tintenbar Diatomite mine)	[Opal] Warwick – Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps: R.E. Brown, H.F. Henley and W.J. Stroud, December, 2001. Published by the Geological Survey of New South Wales.
ⓘ Tintenbar volcanics district	[Opal]
Tintenbar ⓘ Tintenbar opal deposit (Morris's claim)	[Opal] Warwick – Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps: R.E. Brown, H.F. Henley and W.J. Stroud, December, 2001. Published by the Geological Survey of New South Wales.; Smallwood, A. G., Thomas, P., & Ray, A. S. (2008). Comparative analysis of sedimentary and volcanic precious opals from Australia. Journal of Australasian Ceramic Society.
Tweed Heads ⓘ Point Danger	[Opal] R.E. Brown, H.F. Henley and W.J. Stroud: Warwick–Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps, December, 2001. Published by the Geological Survey of New South Wales (GS2001/087).
Wyrallah ⓘ Wyrallah diatomite deposit ?	[Opal] R.E. Brown, H.F. Henley and W.J. Stroud: Warwick–Tweed Heads Exploration Data Package Vol. 2, Mineral occurrence data sheets, occurrence lists and mineral occurrence maps, December, 2001. Published by the Geological Survey of New South Wales (GS2001/087).
St Vincent Co. Ulladulla ⓘ Mollymook	[Opal]
Wentworth Co. Wentworth Kulcurna Station ⓘ Salt Creek	[Opal] Gill, E. D. (1973). Geology and geomorphology of the Murray River region between Mildura and Renmark, Australia. Memoirs of the National Museum of Victoria, 34, 1-97.
Nampoo Station ⓘ Devil's Elbow (Sharp Point)	[Opal] Segnit, E. R. (1973). Minerals from the Murray River region west of Wentworth, NSW, Australia. Memoirs of the National Museum of Victoria, Melbourne, (34), 195.
Yancowinna Co. Broken Hill district ⓘ Broken Hill	[Opal] No reference listed
Broken Hill South Mine (BHS Mine; South Mine) ⓘ Kintore opencut	[Opal-A var: Opal-AN] Birch, W.D., van der Heyden, A. (1997) Minerals of the Kintore and Block 14 open cuts at Broken Hill NSW. Australian Journal of Mineralogy: 3: 23-71.
ⓘ Daydream Mine (Meech's Blow)	[Opal-A var: Opal-AN] The Daydream Mine, G.D. Grose, Bungala Press 2002. The reference refers to minerals collected at the mine and identified by John Leach.
Yungnulgra Co. Gemville ⓘ Gemville Opal Field	[Opal] Aracic, S (1999) Rediscover Opals in Australia.
ⓘ White Cliffs	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages. Bottril, R.S. & Neef, G.. (1998). Mid‐Devonian ultrabasic sill near White Cliffs, New South Wales. Australian Journal of Earth Sciences. 45. 93-96. 10.1080/08120099808728370.
Northern Territory Barkly Region Wauchope Mosquito Creek Wolfram Field ⓘ Mosquito Creek Opal Deposit	[Opal] Benger, J.W. (1990), First and Final Report on Surrendered EL 6673 in the Northern Territory of Australia, 1990
Central Desert Region ⓘ Harts Range (Harts Ranges; Hartz Range; Hartz Ranges)	[Opal]
ⓘ Queensland	[Opal]
Barcoo Shire ⓘ Barcoo River	[Opal] Natural History Museum, London
ⓘ Jundah opal field	[Opal] http://en.wikipedia.org/wiki/Jundah,_Queensland
ⓘ Opalville opal mine	[Opal] http://en.wikipedia.org/wiki/Jundah,_Queensland
Blackall-Tambo Region ⓘ Listowel Downs	[Opal] Rocks & Min.: 8:15.
ⓘ Aladdin mine	[Opal] Rocks & Min.:8:4.
Burke Shire Burketown ⓘ Nicholson River	[Opal-A var: Opal-AN]
City of Mount Isa Gunpowder District Mount Gordon ⓘ Esperanza Z5 Mine (Esperanza deposit)	[Opal] Richardson, S.M. and Day, A.D. (1997) Geology of the Esperanza copper deposit. Proceedings of the 3rd International Mining Geology Conference, Launceston. pg. 51-56
Mount Isa Mount Isa Mines ⓘ Black Star open cut (Black Star pit; Black Star lode)	[Opal] Steve Sorrell Collection
Cloncurry Shire Cloncurry ⓘ Milo Mine	[Opal] Derrick, G.m., Millist, G., Little, M., D'Addario, G.w., Bultitude, J.m., & Wilson, I.h., 1977. Marraba 1:100 000 Geological Map. Bureau Of Mineral Resources, Geology And Geophysics, And Geological Survey Of Queensland
ⓘ Monakoff Mine	[Opal-A var: Opal-AN] Graham Lee Collection
Rosebud Station Mary Kathleen district ⓘ Hardway Mine	[Opal-A var: Opal-AN] Personal collection and shown on photo
Gold Coast City Shire Coolangatta ⓘ Point Danger	[Opal] MacNevin A.A. & Holmes G.G. (1980) Gemstones. Geological Survey of New South Wales, Mineral Industry 18, 2nd edition
ⓘ Currumbin	[Opal] Hall, P. (1988) Australian Mineralogist, Vol 3, April-June 1988, pg. 65.
McKinlay Shire McKinlay ⓘ Cannington Mine (South32 Cannington)	[Opal]
Paroo Shire ⓘ Koroit opal field	[Opal]
ⓘ Yowah opal field	[Opal]
Quilpie Shire Eromanga ⓘ Eromanga Opal Field	[Opal] Martins da Pedra collection. Ingram, J.A. (1968) Notes on opalization in south-western Queensland. Department of National Development, Bureau of Mineral Resources, Geology and Geophysics, Record, 1968/47, 20 pages.
Kyabra Keeroongooloo station ⓘ Friday Mine	[Opal] Rocks & Min.:8:15.
ⓘ Quilpie	[Opal]
Sunshine Coast Region Glasshouse Mountains Province ⓘ Maleny Volcanic Field	[Opal]
Western Downs Region Dalby Kaimkillenbun ⓘ Squaretop Mountain (Black top hill)	[Opal-A var: Opal-AN]
Winton Shire ⓘ Opalton	[Opal]
ⓘ Winton	[Opal] Rob Lavinsky specimen
South Australia Andamooka Ranges ⓘ Andamooka opal fields	[Opal]
ⓘ German Gully	[Opal]
ⓘ Hard Hill opal field	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Horse Paddock diggings	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Treloars opal field	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
Central North ⓘ Coober Pedy	[Opal] Kessler, E. (1983) Kostbarkeit von Coober Pedy oder The Incredible Inedible Opal Pineapple. Mineralien-Magazin, 9/1983, 401-402.; Georgina Gordon, Brian Morris, and Josine Talbot (2014) Logging the Regolith Profile of Cooper Pedy, South Australia. in Geological Society of Australia, 2014 Australian Earth Sciences Convention (AESC), Sustainable Australia. Abstract No 110 of the 22nd Australian Geological Convention.
ⓘ Breakaways	[Opal] Barnes, L.C., (1992), Opal: South Australia's gemstone, Dept. of Mines and Energy, Geological Survey of South Australia, [Parkside, S. Aust.].
ⓘ Dead Horse Gully Field	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Geological Survey of South Australia, Department of Mines and Energy, Handbook No. 5, (Revised ed.) 177 pages.
ⓘ Donnas Rush	[Opal] Barnes, L.C., (1992), Opal: South Australia's gemstone, Dept. of Mines and Energy, Geological Survey of South Australia, [Parkside, S. Aust.].
ⓘ Seventeen Mile field	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
Mobella Station ⓘ Challenger mine	[Opal] Lintern, M. J., & Sheard, M. J. (1999). Regolith studies related to the Challenger gold deposit, Gawler Craton, South Australia. CRC LEME.
Stuart Creek ⓘ Stuart Creek Opal Diggings	[Opal] Thiry, M., & Milnes, A. R. (1991). Pedogenic and groundwater silcretes at Stuart Creek opal field, South Australia. Journal of Sedimentary Research, 61(1).
Eyre Peninsula Middleback Range Iron Knob ⓘ Iron Monarch open cut	[Opal-A var: Opal-AN] Francis, Glyn L. (2010) Minerals of Iron Monarch. OneSteel, Whyalla, Australia, 164 pgs.
ⓘ Tumby Bay	[Opal] Ben Grguric
Flinders Ranges North Flinders Ranges ⓘ Arkaroola Region (Arkaroola Wilderness Sanctuary; Arkaroola Station)	[Opal-A var: Opal-AN] Steve Sorrell Collection; Steve Sorrell Collection
Mawson Plateau - Paralana Hot Springs area ⓘ Paralana Hot Springs	[Opal] Brugger et al. (2005) An active amagmatic hydrothermal system: The Paralana hot springs, Northern Flinders Ranges, South Australia. Chemical Geology, Vol. 222, pg. 35-64.
Mount Fitton homestead ⓘ Pinnacles Mine	[Opal-A var: Opal-AN] Collection of RJ Martin
ⓘ Mt Gee	[Opal-A var: Opal-AN]
Mt Painter area ⓘ Mount Painter No. 2 workings	[Opal-A var: Opal-AN] Brugger, J., Ansermet, S. & Pring, A. (2003) Uranium minerals from Mt Painter, Northern Flinders ranges, South Australia. Australian Journal of Mineralogy, 9(1), 15-31.
Vulkathunha - Gammon Ranges National Park ⓘ O'Donoghue's Castle Mine (O'Donohue's Castle Mine)	[Opal-A var: Opal-AN] Pers. Comm. M. Willoughby. Found on specimen with Olivenite. Collection of M. Willoughby.
Mt Lofty Ranges North Mt Lofty Ranges Barossa Valley Angaston ⓘ Angas Property	[Opal] Gee, L.C.E. & Brown, H.Y.L., (1908), Record of The Mines of South Australia, 4th ed., Government Printer, Adelaide, South Australia.
ⓘ Crinnis Copper Mine	[Opal] Record of Mines - Mine Summary Card No:13, SI5409
Burra ⓘ Burra Burra Copper Mine (Burra Mine; Monster Mine)	[Opal] Grguric, B., Pring, A. & Drew, G. (1994), "The Burra Burra mine, Burra, South Australia", Mineralogical Record, vol. 25, no. 2, pp. 121-129.
Spalding ⓘ Bundaleer area	[Opal-A var: Opal-AN] Personal collection of M. Willoughby.
ⓘ Truro	[Opal]
South Mt Lofty Ranges (Adelaide Hills) ⓘ Hackham	[Opal]
Williamstown Mount Crawford Forest Reserve ⓘ Sailors Gully	[Opal] Gee, L.C.E. & Brown, H.Y.L., (1908), Record of The Mines of South Australia, 4th ed., Government Printer, Adelaide, South Australia.
North West Province ⓘ Broken Leg Waterhole	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages. Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Lambina opal field	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
Mintabie ⓘ Mintabie opal field (Old field)	[Opal] Liesegang, Moritz, and Ralf Milke. (2018) "Silica Colloid Ordering in a Dynamic Sedimentary Environment" Minerals 8, no. 1: 12. https://doi.org/10.3390/min8010012
ⓘ Ouldburra Hill	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Longins Bank diggings	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Sarda Bluff	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages. Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Vesuvius diggings	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
ⓘ Wellbourn Hill	[Opal] Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages. Barnes, L.C., Townsend, I.J., Robertson, R.S., Scott, D.C. (1992) Opal: South Australia's Gemstone. Handbook, No. 5, Department of Mines and Energy, Geological Survey of South Australia, 175 pages.
Northeast ⓘ Marree	[Opal]
ⓘ Dunns Deposit (Willouran Mine)	[Opal-A var: Opal-AN] Collection of M. Willoughby.
Olary Province Boolcoomatta Reserve (Boolcoomata Station) ⓘ Dome Rock Copper Mine	[Opal-A var: Opal-AN] No reference listed
Mt Victor Plumbago Station ⓘ The Ethiudna Mines	[Opal-A var: Opal-AN] J Bosworth, Minsoc SA 1993 Excursion Report
Tasmania Circular Head municipality Cape Grim district ⓘ Trefoil Island	[Opal] Everard, J.L., Calver, C.R., Pemberton, J., Taheri, J., Dixon, G. (1997) Geology of the islands of southwestern Bass Strait. Tasmanian Geological Survey, Record 1997/03, 60 pages plus maps.; Sutherland, F.L., Corbett, K.D. (1967) The Tertiary Volcanic Rocks of Far North-Western Tasmania. Papers and Proceedings of the Royal Society of Tasmania, Vol. 101, 71-92.
Marrawah district Redpa ⓘ Redpa quarry	[Opal] http://www.crocoite.com/locationbulletins/part1/zeolites.pdf
Clarence City Risdon ⓘ Shag Bay	[Opal]
Devonport City municipality Devonport district ⓘ Don Hill	[Opal-A var: Opal-AN] http://www.crocoite.com/locationbulletins/part1/zeolites.pdf
Hobart city ⓘ Lower Sandy Bay	[Opal]
Mt Nelson ⓘ Mt Nelson quarry	[Opal] Bottrill and Baker, 2008, Catalogue of Minerals of Tasmania
Huon Valley municipality Huon-Channel region ⓘ Cygnet district	[Opal] Taheri, J., and Bottrill, R. S., 1998, Porphyry and Sedimentary-hosted Gold Deposits near Cygnet: New Styles of Gold Mineralisation in Tasmania: Unpub Rept, Mineral Resources Tasmania. 1999/01
Weld river district ⓘ Forster Prospect	[Opal] Bottrill, R.S., Baker, W.E. (2008) A Catalogue of the Minerals of Tasmania. Geological Survey Tasmania Bulletin 73, 254 pages.
Southern Islands ⓘ Pedra Branca	[Opal] Bottrill, R.S., Baker, W.E. (2008) A Catalogue of the Minerals of Tasmania. Geological Survey Tasmania Bulletin 73, 254 pages.
Northern Midlands municipality Avoca-Royal George mining district ⓘ Benham plains	[Opal-A var: Opal-AN] Mathew Latham collection
Tasman Municipality ⓘ Lime Bay	[Opal] R Bottrill collection
Waratah-Wynyard municipality Waratah district Waratah ⓘ Mount Bischoff Mine	[Opal] Bottrill, unpub.
West Coast municipality Trial Harbour district ⓘ Heemskirk Falls prospect	[Opal] R Bottrill, unpub.data; Bottrill, R.S., (2015) unpub consultant report, Mineral Resources Tasmania
Victoria Campaspe Shire Corop ⓘ Lake Cooper quarry	[Opal-A var: Opal-AN] crocoite.com
City of Ballarat ⓘ Alfredton	[Opal-A var: Opal-AN] Steve Sorrell Collection
Miners Rest ⓘ Miners Rest Quarry	[Opal] Steve Sorrell Collection
ⓘ Sebastopol	[Opal-A var: Opal-AN] Toby Billing collection
City of Casey Berwick ⓘ Bayview Quarry (Bayview quarries; Berwick Bluestone Quarry)	[Opal]
City of Greater Geelong Anakie ⓘ Mount Anakie	[Opal-A var: Opal-AN] Museum Victoria Mineralogy Collection
ⓘ Eastern Hill	[Opal-A var: Opal-AN] Museum Victoria Mineralogy Collection
City of Hume ⓘ Sunbury	[Opal-A var: Opal-AN] Judy Rowe Collection
ⓘ Emu Creek	[Opal]
City of Latrobe ⓘ Yinnar	[Opal] Curtis, N.J.; Gascooke, J.R.; Johnston, M.R.; Pring, A. (2020) A Review of the Classification of Opal with Reference to Recent New Localities. Minerals 2019, 9, 299.
ⓘ Stony Creek	[Opal]
City of Whittlesea Bundoora ⓘ Boral Limited quarry	[Opal-A var: Opal-AN]
City of Yarra Collingwood Clifton Hill ⓘ Corporation quarries	[Opal-A var: Opal-AN] - Birch, W. D., ed. (1989): Zeolites of Victoria. The Mineralogical Society of Victoria Inc., Special Publication No. 2, Melbourne, Australia, pp. 1-30,92,93,97 & 99
Colac Otway Shire Colac ⓘ Riordan's Quarry	[Opal] Steve Sorrell Collection
ⓘ Cororooke	[Opal] Steve Sorrell Collection
Ondit ⓘ Colac Quarry	[Opal] Steve Sorrell Collection
Corangamite Shire Skipton Mt. Widderin ⓘ Skipton Caves	[Opal] Webb, J. A., Joyce, E. B., & Stevens, N. C. (1982). Lava caves of Australia. In Proceedings of the Third International Symposium on Vulcanospeleology. International Speleological Foundation, Seattle. p74-85.
Golden Plains Shire Lethbridge ⓘ Lethbridge quarry	[Opal] Steve Sorrell Collection
Hepburn Shire Creswick ⓘ Allendale	[Amber] Kirejtshuk, A. G., Merkl, O., & Kernegger, F. (2008). A new species of the genus Pentaphyllus Dejean, 1821 (Coleoptera: Tenebrionidae, Diaperinae) from the Baltic amber and checklist of the fossil Tenebrionidae. Zoosyst Ross, 17, 131-137.
ⓘ Glengower	[Opal]
ⓘ Trentham	[Opal-A var: Opal-AN] Steve Sorrell Collection
ⓘ Trentham Falls	[Opal-A var: Opal-AN] J.D.Hollis. 1979. Some little known zeolite localities in central Victoria. The Australian Mineralogist No.21 April 1979, pp. 101-102
Loddon Shire Brenanah Mount Kooyoora ⓘ White Swan pegmatite mine	[Opal-A var: Opal-AN] Ryan Eagle field collected 2018
ⓘ Mount Hope	[Opal-A var: Opal-AN] Ryan Eagle personal observation 2016
Macedon Ranges ⓘ Spring Hill	[Opal-A var: Opal-AN] Judy Rowe Collection
Macedon Ranges Shire ⓘ Malmsbury	[Opal] Alan Goldstein colln.
ⓘ Malmsbury Quarry	[Opal-A var: Opal-AN] specimen in collection
ⓘ Rollinsons quarry	[Opal-A var: Opal-AN] ex Joan Lamond Collection
ⓘ Riddells Creek	[Opal]
Mansfield Shire Mansfield ⓘ Phosphate Hill	[Opal-A var: Opal-AN] W.D.Birch & D.A.Henry 1993. Phosphate Minerals of Victoria. The Mineralogical Society of Victoria special publication No. 3 pp 67-77
Pyrenees Shire Avoca Lillicur ⓘ Diatomite deposit	[Opal]
Rural City of Wangaratta ⓘ Glenrowan	[Opal-A var: Opal-AN] Steve Sorrell Collection
Greta South ⓘ Greta South turquoise field	[Opal-A var: Opal-AN] Birch, W.D. & Henry D.A. (1993) Phosphate Minerals of Victoria. The Mineralogical Society of Victoria - Special publication No.3 (192p) pp.83-90.
Southern Grampians Shire ⓘ Glenthompson	[Opal-A var: Opal-AN] Jon Mommers collection
Surf Coast Shire ⓘ Armytage Quarry	[Opal] Steve Sorrell Collection
Swan Hill Rural City Lake Boga ⓘ Lake Boga granite quarry	[Opal-A var: Opal-AN] Steve Sorrell Collection W.D.Birch 1977. Minerals in the pegmatitic phase of the Lake Boga Granite. The Australian Mineralogist No. 10 June/July 1977, pp. 44-46
Towong Shire Dartmouth Morass Creek gorge ⓘ Wombat Hole prospect (Wombat Hole mine)	[Opal-A var: Opal-AN] Steve Sorrell collection
Yarra Ranges Shire Lilydale ⓘ Cave Hill Quarry (David Mitchell Limestone Quarry; Lilydale Quarry)	[Opal-A var: Opal-AN] Steve Sorrell Collection
ⓘ Western Australia	[Opal]
Carnarvon Shire ⓘ Gascoyne River	[Opal] Carr, P.F., Peleckis, G., Buckman, S., Archer, G. (2021): Goethite pseudomorphs after marcasite from the Gascoyne River, Western Australia. Australian Journal of Mineralogy 22 (2), 5-12.
City of Karratha ⓘ Peawah gold prospect	[Opal] Simpson, Edward S. (1952) Minerals of Western Australia Vol 3 (Facsimile ed. 1984). Hesperian Press, Carlisle, Western Australia p 684.
Coolgardie Shire Binneringie Station ⓘ Binneringie opal deposit	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia. Geological Survey of Western Australia, Mineral Resources Bulletin 25, 306 pages.
Coolgardie Grosmont district ⓘ Grosmont Mica Mine	[Opal] Jacobson., M (2007), Pegmatites of WA
ⓘ Williams Opal Mine (Three Mile Hill Mine)	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia. Geological Survey of Western Australia, Mineral Resources Bulletin 25, 306 pages.
ⓘ Dandaragan Shire	[Opal] Geology of the Northern Perth Basin, Western Australia- a field guide; A.J. Mory, D.W. Haig, S. Mcloughlin, R.M. Hockisly; Department of Industry and Resources; Perth 2005
Cervantes ⓘ Lake Thetis	[Opal] Geology of the Northern Perth Basin- a field guide; A.J. Mory, D.W. Haig, S. McLoughlin, R.M. Hocking; Dept of Industry and Resources, Western Australian Government; Perth 2005; p51
Dundas Shire ⓘ Norseman	[Opal] Kim McDonald collection
ⓘ Norseman opal mine	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V., (2013): Gemstones of WA, Geological Survey of WA
East Pilbara Shire Braeside lead field ⓘ Ragged Hills Mine	[Opal] Blockley, J.G. (1971) The lead, zinc and silver deposits of Western Australia. Geological Survey of Western Australia, Mineral Resources Bulletin 9, 234 pages. Williams, I.R., Trendall, A.F. (1998) Geology of the Braeside 1:100,000 sheet: Western Australia Geological Survey, 1:100,000 Geological Series Explanatory Notes, 39 pages. Ferguson, K.M. (1999) Lead, zinc and silver deposits of Western Australia. Western Australia Geological Survey, Mineral Resources Bulletin 15, 314 pages. Hancock, E.A., Downes, P.J., Bevan, A.W.R. (2007) Secondary Minerals from the Braeside Lead Field Pilbara Western Australia. Australian Journal of Mineralogy, 13(2), 55-65. Simpson Mineral Collection of the Western Australian Museum.
Nullagine ⓘ Lionel chrysotile deposit	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 2, p26
Weeli Wolli Creek Area Mining Area C ⓘ Area C mine	[Opal-A var: Opal-AN] J M Bennett Collection
Gingin Shire ⓘ Gingin (Molecap Hill; Poison Hill; MacInytre Gully)	[Opal] On Gearkstite at Gingin, Western Australia: Mineralogical Magazine, Vol 19, May 1920, pp23-39
Goomalling Shire ⓘ Thomas and Truscotts mine	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of WA, Geological Survey of WA
Kalgoorlie-Boulder Shire Black Flag Goldfield Grant's Patch ⓘ Black Flag Road opalite area	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of WA, Geological Survey of WA
ⓘ Grants Patch opalite area	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of WA, Geological Survey of WA
Mount Pleasant ⓘ Lady Bountiful Extended Gold Mine	[Opal] De Broekert, P (2003). The Lady Bountiful Extended Gold Deposit Western Australia, CRC LEME, 2003
Bulong Goldfield ⓘ Bulong Area magnesite deposits	[Opal] Feldtmann, F.R. (1919), The Magnesite Deposits of Bulong. North-East Coolgardie Goldfield, Geological Survey of Western Australia, Bulletin 82, 1919
ⓘ Bulong Ni Mine	[Opal] Kim McDonald collection
ⓘ Bulong opal deposits	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of WA, Geological Survey of WA
ⓘ Taurus chrysoprase deposit	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V. (2013): Gemstones of WA, Geological Survey of WA
Cowarna Downs Station ⓘ Cowarna opal mine	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of Western Australia, Geological Survey of Western Australia
Mount Monger Goldfield ⓘ Mount Monger	[Opal] Kalgoorlie Miner newspaper (1920), Mt. Monger Field. Geological Report, 25/06/1920
Laverton Shire Erilstoun Goldfield ⓘ Baneygo Gold Mine	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 306 (assumed to be Banego Erilstoun in Simpson).
ⓘ Murrin Murrin Ni-Co Mine (Anaconda Nickel mine)	[Opal] http://mrdate.usgs.gov/laterite/show-laterite.php?rec_id=8
White Cliffs Station ⓘ Unnamed opal deposit	[Opal] Pardieu, V. (2011) Common opal from Laverton, Western Australia. Gems & Gemology, Winter 2011, 319-320.
ⓘ White Cliffs fire opal deposits	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p321, 1948
Leonora Shire Leinster ⓘ Goanna Patch Mining Area	[Opal] Grguric, B.A. (2009) The gold nugget bonanza of Goanna Patch, Western Australia. Australian Journal of Mineralogy. Vol. 14, pg. 55-60.
Meekatharra Shire Bulloo Downs Station ⓘ Koode Magi prospect	[Opal] Marston, R.J. (1979) Copper Mineralization in Western Australia. Mineral Resources Bulletin 13, Geological Survey of Western Australia, 208p.
Milgun Station ⓘ Milgun Variscite Mine	[Opal] Peter Downes, WA Museum
Mount Gould Station ⓘ Mount Seabrook Talc Mine	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia. Geological Survey of Western Australia, Mineral Resources Bulletin 25, 306p.
Mount Padbury Station ⓘ Discovery U Quarries	[Opal] http://www.fairstarresources.com/mtpadbury.php
Sylvania Station ⓘ Coobina Chromite Mine (Jimblebah; Jimblebar; Murramunda)	[Opal] Grguric, B.A., Jones, S., Gray, S. (in press) Chromian clinochlore from Coobina, Pilbara Province, Western Australia. Australian Journal of Mineralogy.
Menzies Shire ⓘ Comet Vale	[Opal] Grguric, B.A., Pring, A., Bevan, A.W.R., Downes, P.J. (2006): The Minerals of Comet Vale Western Australia, Australian Journal of Mineralogy (2006):12: 9-23
ⓘ Blue Speck Creek	[Opal] Fetherston, J. M., Stocklmayer, S. M. and Stocklmayer, V. C. (2013): Gemstones of Western Australia. Mineral Resources Bulletin 25, Geological Survey of Western Australia, Perth, Australia, 133 pp.
Davyhurst Goldfield Callion ⓘ Glasson Gold Mine (BC Pit)	[Opal] Llorca, S.M. (1998), Mineralogy and Geochemistry of the Galsson Gold Deposit Callion Yilgarn Block Western Australia, CRC LEME, 1998
Diemals Station ⓘ Evanston Gold Mine	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 613
Mount Magnet Shire Mount Magnet East Magnet Goldfield ⓘ Primrose Gold Mine	[Opal] The Inquirer and Commercial News newspaper (Perth) (1895), Mount Magnet Fields, 20/12/1895
Lennonville Goldfield ⓘ Welcome Gold Mine	[Opal] The Inquirer and Commercial News newspaper (Perth) (1896), The Sensational Welcome Mine, 21/08/1896
Murchison Shire Byro Station ⓘ Bulgarro opal mine (Bulgaroo opal mine)	[Opal] Fetherston, J., Stocklmater, S., Stocklmayer, V(2013): Gemstones of WA, Geological Survey of WA
ⓘ Iniagi Well (Imagi Well Mine)	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia - Mineral Resources Bulletin 25, Geological Survey of Western Australia (2013): p119
ⓘ Meegea	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia - Mineral Resources Bulletin 25, Geological Survey of Western Australia (2013): p119
Nookawarra Station ⓘ Mount Taylor 1 prospect	[Opal] Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia - Mineral Resources Bulletin 25, Geological Survey of Western Australia (2013) p277.
Northam Shire Northam ⓘ Mount Dick	[Opal-A var: Opal-AN] Fetherston, J., Stocklmayer, S., Stocklmayer, V(2013): Gemstones of WA, Geological Survey of WA
Northampton Shire ⓘ Northampton	[Opal] Downes, P.J., Deacon, G.L., Bevan, A.W.R., Blockley, J., Grguric, B.A., Verrall, M. (2017), Minerals of the Northampton Lead-Copper Field Western Australia, Australian Journal of Mineralogy, Vol. 18 (1), pp 40, June 2017
Perenjori Shire Karara Conservation Reserve ⓘ Rothsay beryl pegmatites (Seleka; Perenjori Beryl Mine)	[Opal-A var: Opal-AN] Calderwood, M.A., Grguric, B.A., Jacobson, M.I., (2007). Guidebook to the Pegmatites of Western Australia. Hesperian Press, Carlisle, Western Australia.
ⓘ Rothsay Mine (Woodley's Find)	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V(2013): Gemstones of WA, Geological Survey of WA
Weelhamby Lake ⓘ Ninghanboun Hills	[Opal] Fetherston, J., Stocklmayer, S., Stocklmayer, V.(2013): Gemstones of WA, Geological Survey of WA
ⓘ Ninghanboun Hills serpentinite	[Opal] Simpson, E.S. (1932) Contributions to the mineralogy of Western Australia, (7) Variscite (redondite) and leucophosphite (Sp. nov.), Ninghanboun Hills, S.W.. Journal of the Royal Society of Western Australia: 18: 69-74.; Palache, C., Berman, H., & Frondel, C. (1951) The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 936.
Sandstone Shire Youangarra Goldfield (Curran's Find) ⓘ Penny West Gold Mine	[Opal] Jorgensen, G.C., Downes, P.J., Deacon, G.L., Verall, M. (2017), Wulfenite from the Penny West Gold Mine near Youanmi: a new occurrence for Western Australia, Australian Journal of Mineralogy, Vol 18 (1), pp 23-33, June 2017
Upper Gascoyne Shire ⓘ Mooloo Downs Station	[Opal] Moolooite, a Naturally Occurring Hydrated Copper Oxalate; R.M. Clarke and I.R. Williams; Mineralogical Magazine, June 1986, Vol 50, pp 295-298
ⓘ Moolooite location	[Opal] Clarke, R.M., Williams, I.R. (1986) Moolooite, a naturally occurring hydrated copper oxalate from Western Australia, Mineralogical Magazine (June 1986) Vol.50, pp295-298.
Mount Phillip Station (Mount Phillips Station) ⓘ Mount Phillips Amethyst Mine (Gascoyne Amethyst Mine; Soklich Amethyst Mine)	[Opal] Kim Macdonald
Yinnietharra ⓘ Tomkap tourmaline mines (Soklich)	[Opal] Locality description
ⓘ Yinnietharra Dravite mine (South Open Cut)	[Opal] Bridge, P.J., Daniels, J.L., Pryce, M.W. (1977) The dravite crystal bonanza of Yinnietharra, Western Australia. The Mineralogical Record, 8(2), 109-111.
ⓘ Yinnietharra Dravite North mine	[Opal] Fetherston, J.M., Stocklmayer, S., Stocklmayer, V.C.(2013): Gemstones of Western Australia- mineral resources bulletin 25, Geological Survey of Western Australia (2013): 57
Westonia Shire Westonia ⓘ Edna May Gold Mine	[Opal] Simpson, E.S., (1948) Minerals of Western Australia. Volume 1-3. Government Printer, Perth.
Wiluna Shire Wiluna Wiluna Mining Project ⓘ Bulletin Mine	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 324 (listed as Wiluna GM in Simpson)
Yalgoo Shire Minjar Gold District ⓘ Golden Monarch (Monarch; Mug's Blow; Mug's Luck)	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 305
Paynes Find ⓘ Mount Edon	[Opal-A var: Opal-AN] Pegamtites of Western Australia; M Jacobson, M Calderwood, B Grguric; Hesperian Press, Perth, 2007.
Yilgarn Shire Bullfinch ⓘ Copperhead Gold Mine	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p320
ⓘ Mount Jackson Goldfield	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 1-p331, Vol 2- p218, p422, p540, Vol 3- p322, 1948
Parker Range Goldfield ⓘ Mount Caudan iron ore and gold prospect	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 320
Southern Cross ⓘ Maori Lass Gold Mine	[Opal] The Southern Cross Times newspaper (1913), The Maori Lass, 11/06/1913
Yellowdine ⓘ Mount Palmer Gold Mine (Palmer's Find)	[Opal] Simpson, E.S. (1948), Minerals of Western Australia, Vol 3, p 322

Austria
Burgenland Oberpullendorf District Markt Sankt Martin Pauliberg ⓘ Basalt quarry	[Opal-A var: Opal-AN] Schebesta, K. (1983) Der Pauliberg - Eine Micromountfundstelle vor den Toren Wiens. Eisenblüte, 4 (10), 8-11.; U. Kolitsch, W. Postl, H.-P. Bojar and W. Trattner (2009): Die Mineralvorkommen im Basalt des Pauliberges. In: Autorenkollektiv (Red. M. A. Götzinger und P. Huber) (2009): Die Mineralien des Burgenlandes - Geologie, Mineralogie und mineralische Rohstoffe. – Wissenschaftliche Arbeiten aus dem Burgenland, Band 126, Amt der Burgenländischen Landesregierung, Abteilung 7 - Landesmuseum, Eisenstadt, 83-99.; Kolitsch, U., Postl, W., Bernhard, F., Bojar, H.-P., Trattner, W. (2019): 2152) Ägirin, Albit, Alunit, Baryt, Calcit, Chalkopyrit, Cordierit, Corkit, Cristobalit, Diopsid, Dolomit, Dravit, Fayalit, Fluorapatit, Gehlenit, Gips, Goethit, Hämatit, Hauyn, Jarosit, Kaolinit, Kupfer, Laihunit(?), Magnesit, Magnetit, Montmorillonit, Mullit, Natroalunit, Natrojarosit, Nephelin, Opal (Hyalit), Plumbojarosit, Phosphohedyphan, Pyrit, Pyromorphit, Pyrrhotin, Quintinit(?), Rhönit, Rutil, Sodalith, Todorokit, Topas, Tridymit und Uricit aus dem Steinbruch am Pauliberg bei Landsee, Burgenland. Pp. 310-319 in Walter, F. et al. (2019): Neue Mineralfunde aus Österreich LXVIII. Carinthia II, 209./129., 237-362.
Oberwart District Badersdorf ⓘ Holler quarry	[Opal-A var: Opal-AN] Postl, W., Moser, B., Brandstätter, F., Niedermayr, G. (1991): 844. Analcim, Azurit, Chalkopyrit, Chlorit, Chrysokoll, Cuprit, Epsomit, Granat, Hyalit, gediegen Kupfer, Malachit und Siderit von Badersdorf, Burgenland (ein Vorbericht). Pp. 168-169 in Niedermayr, G. et al. (1991): Neue Mineralfunde aus Österreich XL. Carinthia II, 181./101.: 147-179.; Natural History Museum Vienna collection; Götzinger, M. A. & Huber, P. (2009)
ⓘ Unnamed quarry	[Opal-A var: Opal-AN] Tuma, F. (1991)
Bernstein ⓘ Pechgraben	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Kohfidisch	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Csaterberge (Csater-Berge)	[Opal] Kümel, F. (1957)
ⓘ Opal occurrence	[Opal] Kümel, F. (1957): Der Süßwasseropal der Csatherberge im Burgenlande. Jahrb. Geol. B.-A., 100 (1), 1-66.
Carinthia Klagenfurt am Wörthersee Ehrentaler Berg ⓘ A2 Highway tunnel	[Opal] F. Brandstätter: Carinthia II 184./104.:248-252 (1994)
Kreuzbergl massif Falkenberg ⓘ A2 Highway tunnel (Falkenberg tunnel)	[Opal-A var: Opal-AN] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Sankt Veit an der Glan District Flattnitz ⓘ Haidnerhöhe	[Opal-A var: Opal-AN] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Guttaring ⓘ Sonnberg	[Amber] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Hüttenberg Hüttenberger Erzberg ⓘ Gossen section	[Opal] H. Meixner: Der Karinthin 9:184-189 (1950)
Klein Sankt Paul ⓘ Sittenberg	[Amber] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Spittal an der Drau District Radenthein Millstätter Alpe ⓘ Magnesite Mine	[Opal] Pichler, A. (2009) Bergbau in Westkärnten, Eine Bestandsaufnahme der noch sichtbaren Merkmale der historischen Bergbaue in Westkärnten. Verlag des Naturwissenschaftlichen Vereins für Kärnten, Klagenfurt, Sonderheft 63, 416 pages [in German].
Villach-Land District Fresach Laas ⓘ Feldspar quarry	[Opal-A var: Opal-AN] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Villach Zauchen ⓘ Kornberg	[Opal] H. Meixner: Carinthia II 171./91.:35-36 (1981)
Wolfsberg District Bad Sankt Leonhard im Lavanttal Mica Mines ⓘ Peter Mine	[Opal-A var: Opal-AN] Meixner, H. (1952): Neue Mineralfunde in den österreichischen Ostalpen XII. Carinthia II, 142./62, 27-46.; F. Walter (1984)
Frantschach-Sankt Gertraud Brandrücken ⓘ Spodumene prospect	[Opal-A var: Opal-AN]
Fraßgraben ⓘ Fraßgraben quarry (Gall quarry; Modre quarry)	[Opal] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Sankt Andrä Großer Speikkogel ⓘ Schloß Alp (Relais station)	[Opal] G. Weissensteiner: Der Karinthin 63:183-186 (1970)
Sankt Paul im Lavanttal Kollnitz ⓘ Basalt quarry	[Opal] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Wolfsberg Sankt Stefan ⓘ Lignite deposit	[Amber] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995
Lower Austria Baden District Enzesfeld-Lindabrunn ⓘ Jauling lignite deposit	[Amber] V. R. v. Zepharovich: Sitzungsber. kais. Akad. Wiss. Wien 16:366 (1855)
Bruck an der Leitha District Bad Deutsch-Altenburg Pfaffenberg hill ⓘ Hollitzer quarry	[Opal] Niedermayr, Gerhard & Seemann, Robert (1974): Vorläufiger Bericht über sedimentpetrographische Untersuchungen an Höhlensedimenten des Karstgebietes Pfaffenberg bei Bad Deutsch-Altenburg (Niederösterreich). - Die Höhle, 25, 3-11, Wien.
Hollabrunn District Maissau Limberg ⓘ Diatomite pit	[Opal] Götzinger, M. A., Beran, A. & Libowitzky, E. (1994): Exkursion A: Mineralvorkommen und Lagerstätten im östlichen Waldviertel. Mitt. Österr. Mineral. Ges. 139, 389-405.
Oberdürnbach ⓘ Diatomite pit	[Opal] Götzinger, M. A., Beran, A. & Libowitzky, E. (1994): Exkursion A: Mineralvorkommen und Lagerstätten im östlichen Waldviertel. Mitt. Österr. Mineral. Ges. 139, 389-405.
Pulkau Leodagger ⓘ Granite quarry	[Opal-A var: Opal-AN] C.Auer (2018)
Ravelsbach Parisdorf ⓘ Diatomite pit	[Opal] ötzinger, M. A., Beran, A. & Libowitzky, E. (1994): Exkursion A: Mineralvorkommen und Lagerstätten im östlichen Waldviertel. Mitt. Österr. Mineral. Ges. 139, 389-405.
Horn District Brunn an der Wild Atzelsdorf ⓘ Marble quarry	[Opal] Pristacz, H., jun., Kolitsch, U., Löffler, E., Knobloch, G., Prayer, A. & Thinschmidt, A. (2011): 1696) Calcit, Natrojarosit, Palygorskit, Pyrit, Siderit und andere Mineralien aus dem Marmorbruch Atzelsdorf, Brunn an der Wild, Waldviertel. Pp. 160-161 in Niedermayr, G. et al. (2011): Neue Mineralfunde aus Österreich LX. Carinthia II, 201./121., 135-186.
Dietmannsdorf an der Wild ⓘ Serpentinite quarries	[Opal] Kugler, A. (1995): Waldviertel Aktuell: Dietmannsdorf. MEFOS Nr. 10, 4.
Drosendorf-Zissersdorf Pingendorf ⓘ Serpentinite quarry	[Opal] Niedermayr, G. (1990): Eine bemerkenswerte Zeolithparagenese aus einem Serpentinitsteinbruch bei Pingendorf in Niederösterreich. Mineralien-Welt, 1 (2), 31-34.
ⓘ Wolfsbach	[Opal] Niedermayr, G. (1986): 633. Diaspor, Harmotom, Korund und Prehnit aus dem Bereich von Wolfsbach, SE Drosendorf, Niederösterreich. Pp. 532-534 in Niedermayr, G., B. Moser, W. Postl & F. Walter (1986): Neue Mineralfunde aus Österreich XXXV. Carinthia II, 176./96., 521-547.
ⓘ Zissersdorf	[Opal] Albert Prayer collection
Gars am Kamp ⓘ Wanzenau	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Geras Kottaun ⓘ Unnamed quarry ("Andradite quarry")	[Opal-A var: Opal-AN] Kolitsch, U., Knobloch, G., Schillhammer, H. & Löffler, E. (2013): 1814) Aikinit, Albit, Amphibol, Andradit, Azurit, Chalkopyrit, Epidot, Hedenbergit, Hyalith, Magnetit, Malachit, Scheelit, Titanit und Quarz aus einem neuen, kleinen Steinbruch nördlich Kottaun bei Geras, Waldviertel, Niederösterreich. Pp. 127-128 in Niedermayr, G. et al. (2013): Neue Mineralfunde aus Österreich LXII. Carinthia II, 203./123., 91-146.
ⓘ Japons	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Langau ⓘ Chalcedony occurrence	[Opal] Kolitsch, U. (2021): 2212) Chalkopyrit, Cristobalit, Polydymit, Sobolevskit und Sperrylith von Langau bei Geras, Waldviertel, Niederösterreich. Pp. 249-251 in Walter, F. et al. (2021): Neue Mineralfunde aus Österreich LXX. Carinthia II, 211./131., 187-276.
Röhrenbach Winkl ⓘ Marble quarries (incl. Renz Quarry; Bundesheer Quarry)	[Opal] Kolitsch, U., Brandstätter, F., Löffler, E., Knobloch, G., Prayer, A., Pristacz, H., jun. & Thinschmidt, A. (2011): 1697) Die Mineralien der Marmorbrüche bei Winkl, Neupölla, Waldviertel. Pp. 161-163 in Niedermayr, G. et al. (2011): Neue Mineralfunde aus Österreich LX. Carinthia II, 201./121., 135-186.
Krems-Land District Albrechtsberg an der Großen Krems ⓘ Klein-Heinrichschlag	[Opal] Fechner, K. and Götzinger, M. A. (1985): Zur Mineralogie eines Korund-führenden Pegmatites und seiner Reaktionszonen zum Serpentinit (Kl.-Heinrichschlag W Krems, Niederösterreich). Mitt. Österr. Mineral. Ges. 130, 45-56.
Krumau am Kamp Tiefenbach ⓘ Kyanite occurrence	[Opal] RIEDEL, Christian (2008): Glanz und Schönheit - alte und neue Schmuckstein-Materialien aus dem Waldviertel.- In: STEININGER, Fritz F. (Hrsg.): Waldviertel - Kristallviertel. Die steinerne Schatzkammer Österreichs - Gesteine und Mineralien des Waldviertels, Schriftenr. Waldv. Heimatb., 49, 115-123, Horn.
Maria Laach am Jauerling Zintring ⓘ Seebichl	[Opal-A var: Opal-AN] Harald Schillhammer collection
Mühldorf ⓘ Amstall	[Opal-A var: Opal-AN] peter neschen collection
ⓘ Graphite quarry	[Opal-A var: Opal-AN] peter neschen collection;
ⓘ Marble quarry (Thalinger quarry; Hausbruch)	[Opal-A var: Opal-AN] peter neschen collection
ⓘ Road cut	[Opal-A var: Opal-AN] peter neschen collection; ;
ⓘ Weinberg Middle	[Opal] Goldmann, C. & Löffler, E. (2008): Die Mineralienfundstellen des Graphitbergbaues Amstall, NÖ. MEFOS 19/35, 4-34, A-D.
ⓘ Trandorf	[Opal] Natural History Museum Vienna collection
Sankt Leonhard am Hornerwald Dürrenberg (Dürnberg) ⓘ Milk opal occurrence	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Serpentinite outcrops	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Schönberg am Kamp Plank am Kamp ⓘ Calcsilicate occurrence	[Opal] Erwin Löffler collection
Melk District Persenbeug-Gottsdorf Loja ⓘ Quarry II	[Opal] Löffler, E. & Kolitsch, U. (2011): Die Mineralien der Loja bei Persenbeug, Niederösterreich(I). Mineralien-Welt. 22 (3): 73-84
Raxendorf Feistritz ⓘ Graphite mine	[Opal] Holzer, H. & Zirkl, E. J. (1963): Über einige weitere niederösterreichische Graphitlagerstätten. Verh. Geol. B.-A., 1963, 79-91.
Sankt Oswald ⓘ "In der Gleisen" quarry (Yspertal; Ispertal; Unterfell)	[Opal] GÖTZINGER, Michael A. (1987b): Vermiculitvorkommen der Böhmischen Masse in Österreich und ihre Entstehung.- Mitt. Österr. Miner. Ges., 132, 135-156, Wien.
Mödling District Perchtoldsdorf ⓘ Endlwehr quarry	[Amber] Wessely, C. (1908): Mineralogische Spaziergänge eines Wieners. Wiener Urania 1/23, 205 - 208, Wien.
Sankt Pölten-Land District Hafnerbach Hengstberg ⓘ Graphite deposit	[Opal] Kolitsch, U., Löffler, E., Schillhammer, H. & Knobloch, G. (2015): 1944) Allophan, Almandin, Apatit, Calcit, Diopsid, dravitischer Turmalin, Felsőbányait, Gips, Halotrichit, Jarosit(?), Klinozoisit, Melanterit, Mikroklin, Natrojarosit, Opal, Prehnit, Rutil, Sillimanit, Skapolith, Titanit, Tremolit, V-haltiger Muskovit(?) und Zirkon vom ehemaligen Graphitbergbau Hengstberg bei Hafnerbach im Mostviertel, Niederösterreich. Pp. 254-257 in Niedermayr, G. et al. (2015): Neue Mineralfunde aus Österreich LXIV. Carinthia II, 205./125., 207-280.
Karlstetten ⓘ Obermamau chalcedony occurrence	[Opal] HAMMER & ĆORIĆ (2007): 1501) Chalcedon von Obermamau nördlich von St. Pölten, Niederösterreich. Pp. 171-173 in NIEDERMAYR et al. (2007): Neue Mineralfunde aus Österreich Austria LVI. – Carinthia II, 197./117.: 149-190. (in German)
ⓘ Wilhelmsburg	[Amber] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Waidhofen an der Thaya District Dobersberg ⓘ Dobersberg	[Opal] Weiss, A. (1960): Drei Waldviertler Mineralfundstellen. Karinthin, 41, 112-115.
Raabs an der Thaya Eibenstein an der Thaya ⓘ Hengl quarry	[Opal-A var: Opal-AN] Harald Schillhammer collection; Kolitsch, U., Schillhammer, H. & Lamatsch, P. (2015): 1936) Analcim, Axinit-(Fe), Chamosit, Datolith, Gips, Heulandit-Ca, Hyalit, Jarosit, Klinochlor, Klinoptilolith-Ca, Laumontit, Malachit, Molybdänit, Siderit, Sphalerit und Uraninit vom Steinbruch Hengl bei Eibenstein an der Thaya, Waldviertel, Niederösterreich. Pp. 243-245 in Niedermayr, G. et al. (2015): Neue Mineralfunde aus Österreich LXIV. Carinthia II, 205./125., 207-280.
ⓘ Gimpelfeld	[Opal-A var: Opal-AN] Kolitsch, U. & Schillhammer, H. (2014): 1881) Amphibol, Apatit, Chabasit, Chlorit, Diopsid, Epidot, Granat, Hamatit, Hyalith, Ilmenit, Limonit, Magnetit, Mikroklin, Pyrit, Quarz, Rutil und Titanit vom Gimpelfeld bei Raabs, Waldviertel, Niederösterreich. P. 116 in Niedermayr, G. et al. (2014): Neue Mineralfunde aus Österreich LXIII. Carinthia II, 204./124., 65-146.
ⓘ Grossau	[Opal] Wolfgang Ecker collection
ⓘ Primmersdorf	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Höllgraben	[Opal] Sigmund, A. (1937): Die Minerale Niederösterreichs. 2., neu bearb. und erweit. Aufl., F. Deuticke, Wien und Leipzig, 247 pp.; Natural History Museum Vienna collection
Waldkirchen an der Thaya ⓘ Waldkirchen an der Thaya	[Opal] peter neschen collection; Huber, S., Huber, P. (1977): Mineralfundstellen. Band 8: Oberösterreich, Niederösterreich und Burgenland. - 271 p., München - Innsbruck (Christian Weise, Pinguin).
Zwettl District Kottes-Purk Elsenreith ⓘ Graphite mine	[Opal] Zirkl, E. J. (1961): Vorläufiger Bericht über die mineralogischen Untersuchungen einiger Graphitvorkommen aus dem niederösterreichischen Waldviertel. Verh. Geol. B.-A. 1961, 99-101.
Salzburg Hallein District ⓘ Golling an der Salzach	[Amber] Winkler, W. (2003) Eine mineralogische Besonderheit aus dem Lammertal, Salzburg/Österreich - Fossile Harze aus der Unterkreide, pp. 337-342 in Weidinger, J.T., Lobitzer, H., Spitzbart, I. (Hrsg.) 2003. Beiträge zur Geologie des Salzkammerguts. Gmundner Geo-Studien 2 (ISBN 3-9500193-3-2) Erkudok Institut Museum Gmunden (in German with English abstract).
Kuchl ⓘ Carbonatite outcrops	[Amber] http://www.zobodat.at/pdf/GmuGeoStud_2_0337-0342.pdf
Scheffau am Tennengebirge ⓘ Grubach	[Amber] http://www.ambertop.de/weltweit.html
Salzburg-Umgebung District Anthering Anthering - Muntigl area ⓘ Sandstone quarries	[Amber] On exhibit in the Museum "Haus der Natur", Salzburg.
St. Johann im Pongau District Bad Gastein Böckstein ⓘ Municipal quarry (Dick quarry)	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Naßfeld valley Kniebeißgraben ⓘ Unnamed adit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Kreuzkogel massif Radhausberg ⓘ Paris adit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
ⓘ Pasel adit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
ⓘ Schleier fall tunnel	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Siglitz - Bockhart gold mining district ⓘ Bockhart adit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
ⓘ Siglitz adit (Imhof-Unterbau adit; Imhof adit)	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
ⓘ Thermal water spa	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Bad Hofgastein ⓘ Schloss Alp ?	[Opal] Kolitsch, U. and Schachinger, T. (2019): 2119) Aktinolith, Calcit, Epidot, Fluorapatit, Hydroxylapatit(?), Manganoxide, Molybdänit, Opal(?), Pyrophanit, Quarz, Rhodochrosit, Rhodonit, (Linnéit-)Siegenit, Spessartin, Titanit und Zirkon von einer metamorphen Manganmineralisation auf der Schlossalm bei Bad Hofgastein, Gasteiner Tal, Hohe Tauern, Salzburg. Pp. 273-275 in Walter, F. et al. (2019): Neue Mineralfunde aus Österreich LXVIII. Carinthia II, 209./129., 237-362.
Mühlbach am Hochkönig Mitterberg mining district ⓘ Anna adit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Tamsweg District Lessach ⓘ Bodenmoosgraben talc mine	[Opal] A. Strasser: Die Minerale Salzburgs (1989)
Zell am See District Bramberg am Wildkogel Nasenkopf mountain Leckbachgraben ⓘ Emerald deposit	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs (1989)
Mittersill Mittersill Scheelite deposit ⓘ Western ore field	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Neukirchen am Großvenediger Abichl Alp - Beryller area ⓘ Beryller	[Opal-A var: Opal-AN] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Hopffeld area ⓘ Hopffeldboden	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs (1989)
Uttendorf Enzingerboden Tauernmoos lake ⓘ Seewände quarry ?	[Opal-A var: Opal-AN] A. Strasser: Die Minerale Salzburgs, 1989
Styria Bruck-Mürzzuschlag District Kapfenberg Tanzenberg ⓘ S6 motorway tunnel (Tanzenberg tunnel)	[Opal] Postl, W. et al. (1985)
Tragöß-Sankt Katharein Oberdorf (Oberdorf an der Laming) Oberdorf magnesite deposit ⓘ Kaintaleck Mine (Kaintalegg Mine; Hohenburg deposit)	[Opal] Gerald Gesselbauer (2010)
ⓘ Wiesergut Mine (Wieser Mine)	[Opal] Gerald Gesselbauer (2010)
Deutschlandsberg District Bad Schwanberg Glashütten ⓘ Fuchskogel	[Opal] Natural History Museum Vienna collection
ⓘ Hartner quarry	[Opal-A var: Opal-AN] Aufschluss 1972(SB), 43-47
ⓘ Rostock creek	[Opal-A var: Opal-AN] Taucher+Hollerer (2001)
Schwarze Sulm ⓘ Müllerbauer	[Opal-A var: Opal-AN] Weissensteiner, G. (1975) : Uranmineralien der Koralpe. In : Mineralogie Mitteilungen Band 42,Joanneum, Graz, p.27(283).
Deutschlandsberg ⓘ Laßnitzgraben	[Opal-A var: Opal-AN] Weninger, H. (1976): Mineral-Fundstellen Band 5: Steiermark und Kärnten. Chr. Weise Verlag, München, 231 pp.
Osterwitz ⓘ Kuppergrund	[Opal-A var: Opal-AN] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Schwagbauer (Schwoagbauer)	[Opal-A var: Opal-AN] Koritnig, S. ZB1. f. Min. A,1939
ⓘ Stoffhütte pegmatite	[Opal] Postl & Moser (1988)
Eibiswald ⓘ Lignite deposit	[Amber] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Sankt Oswald ob Eibiswald Krumbach ⓘ Polanz quarry (Mauthnereck)	[Opal-A var: Opal-AN] Meixner, H. (1937) : Neue Mineralfunde in den österreichischen Ostalpen. IX. In : Mitteilungen des Naturwissenschaftlichen Vereines für Steiermark, Band 74, 1937
Leibnitz District Oberhaag Lieschengraben ⓘ Aldrian quarry (Hofstatt quarry)	[Opal-A var: Opal-AN] peter neschen collection
Wildon Weitendorf ⓘ Basalt quarry	[Opal-A var: Opal-AN] Aufschluss 1972(SB), 76-79
Leoben District ⓘ Kraubath an der Mur	[Opal] Alker, A. (1972) Mineralien aus der Ultramafit-Masse von Kraubath. Der Aufschluß: 22: 80-83.
Wald am Schoberpass ⓘ Haider quarry	[Opal] Josef Taucher & Christine Elisabeth Hollerer (2012): Chrysokoll und Opal mit Tetraedrit aus dem Steinbruch der Gebrüder Haider nördlich Wald am Schoberpaß, Steiermark. Der Steirische Mineralog 26, 54.
Liezen District Landl Gams bei Hieflau ⓘ Sulzbach	[Amber] peter neschen collection
Murau District Teufenbach-Katsch Katsch an der Mur ⓘ Schwarzenberg quarry	[Opal] http://www.markasit070752.ws24.cc/text_62520295_60708465_19667850_deutsch.html
Murtal District Spielberg Ingering valley ⓘ Holzbrücken mill	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Südoststeiermark District Bad Gleichenberg Klausen ⓘ Schlarbaum quarry	[Opal-A var: Opal-AN] Aufschluss 1972(SB), 52-55
Wilhelmsdorf ⓘ Stradner Kogel	[Opal-A var: Opal-AN] peter neschen collection
Feldbach Gossendorf ⓘ Clay pit	[Opal] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
ⓘ Trass pit	[Opal]
Mühldorf bei Feldbach ⓘ Steinberg	[Opal-A var: Opal-AN] Postl, W., Taucher, J. & Moser, B. (1996): Neue Mineralfunde im oststeirischen Vulkangebiet. Mitt. Abt. Miner. Landesmuseum Joanneum, 60/61, 3-76.
Klöch ⓘ Basalt quarry	[Opal-A var: Opal-AN] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Voitsberg District Köflach ⓘ Köflach - Voitsberg lignite deposit	[Amber] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Maria Lankowitz ⓘ Frei-Gössnitz creek pegmatite outcrops	[Opal] A.Weiß (1972)
Weiz District Rettenegg Prinzkogel (Prinzenkogel) Prinzkogel mines Southern District ⓘ Kaltenegg	[Opal] Jakely, D. et al. (2008)
Tyrol Innsbruck-Land District Navis ⓘ Navis stream (Navis creek) ?	[Opal] Kolitsch, U., Schachinger, T., Auer, C. (2019): 2113) Akatoreit(?), Albit, Ardennit-(As), Ardennit-(V), „Ardennit-(Si)“, Baryt, Brandtit(?) (oder unbenanntes Ca2Mn(AsO4)2?), Coelestin, Fluorapatit, Fluorcalcioroméit, Frankdicksonit(?), Friedelit, Ganophyllit(?), Hämatit, Hausmannit, Hollandit, Jacobsit, Klinochlor, Kutnohorit, Manganberzeliit, Manganiandrosit-(La)-Manganiakasakait-(La)-Mischkristalle, Muskovit, Opal(?), Pennantit, Piemontit(?), Pyrobelonit, Pyrophanit, Quarz, Rhodochrosit, Rhodonit, Sarkinit, Schallerit, Spessartin, Svabit, Tephroit, Tilasit und Tiragalloit vom Navisbach, Navistal, Nordtirol. Pp. 251-260 in Walter, F. et al. (2019): Neue Mineralfunde aus Österreich LXVIII. Carinthia II, 209./129., 237-362.
Telfs ⓘ Kochen valley	[Amber] A. Pichler: Jahrb. k. k. geol. Reichsanstalt (1868)
Kufstein District Kramsach ⓘ Brandenberg	[Amber] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Schwaz District Jenbach ⓘ Pertisau	[Amber] R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993)
Upper Austria ⓘ Gmunden District	[Amber] Peter Neschen specimen
Kirchdorf an der Krems District ⓘ Roßleithen	[Amber] - J.Schadler, in: Bernstein, in Steinkohle der Oberkreide mit wenig Schwefelkies und gelben Anflug von Realgar. (Handschriftliche Aufzeichnungen).
Vorderstoder ⓘ Walchegg	[Amber] - H.Commenda, in: Übersicht der Gesteine und Mineralien Oberösterreichs. 1. Gesteine. Heimatgaue, Zeitschrift für oberösterreichische Geschichte, Landes - und Volkskunde 7, Heft 1, Linz 1926, Seite 41 – 65.
Linz-Land District Enns ⓘ Enns river docks	[Opal-A var: Opal-AN] Peter Neschen Collection
Pucking ⓘ Traun river dam (Traun power plant)	[Opal-A var: Opal-AN] Niedermayr, G. (1987): 672. Heulandit und Opal vom Traunkraftwerk Pucking, Oberösterrich. Pp. 306-307 in NIEDERMAYR, G., BRANDSTÄTTER, F., MOSER, B. & POSTL, W. (1987): Neue Mineralfunde aus Österreich XXXVI. Carinthia II, 177./97., 283-329.; R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993); Kolitsch, U. (2015): 1935) Almandin, Aragonit, Baryt, Heulandit-Na, Klinoptilolith-Na, ein Magnesiochromit-Spinell-Mischkristall und Schwefel vom Traunkraftwerk Pucking, Oberösterreich. Pp. 241-243 in Niedermayr, G. et al. (2015): Neue Mineralfunde aus Österreich LXIV. Carinthia II, 205./125., 207-280.
Rohrbach District Arnreit ⓘ Kicking	[Opal-A var: Opal-AN] - Josef Schadler, in:(Handschriftliche Aufzeichnungen).
Schärding District Sankt Florian am Inn Gopperding ⓘ Granite quarry (Eder quarry)	[Opal-A var: Opal-AN] Kolitsch, U. et al. (2008) Kolitsch, U., Schachinger, T. & Bernhard, F. (2008): 1543: Alpinotype Kluftmineralien (inkl. einer Pseudomorphose von Monazit-(Ce) nach Synchisit-(Ce)?) sowie weitere Mineralisationen aus dem Steinbruch Gopperding bei Schärding, Oberösterreich. In: Niedermayr, G. et al. (2008): Neue Mineralfunde aus Österreich LVII. Carinthia II, 198/118, 254.
Steyr-Land District St. Ulrich bei Steyr ⓘ Farm Eichner	[Opal-A var: Opal-AN] Peter Neschen Collection
Weyer ⓘ Mühlein	[Amber] - G.Geyer, in: Erläuterungen zur Geologischen Karte SW - Gruppe 12, Weyer. Kaiserlich & königliche Geologischen Reichsanstalt, Wien (1911).
Steyr ⓘ Michaeler church	[Amber] Peter Neschen Collection
ⓘ Zwischenbrücken	[Amber] - Gerhard Brandstetter, in: Mineralogische und paläontologische Notizen aus Oberösterreich. OÖ Geonachrichten, Beiträge zur Geologie, Mineralogie und Paläontologie von Oberösterreich.15. Jahrgang (2000), Seite 16 – 22, 7 Abbbildungen. MFOÖ Mineralien - und Fossiliensammler Oberösterreichs mit ARGE Mineralogie, Geologie und Paläontologie im Oberösterreichischen Landesmuseum.

Baltic Sea	[Amber] Van King Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.


Belgium
ⓘ Brussels	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Flanders Antwerp ⓘ Antwerp	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Wommelgem	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
East Flanders ⓘ Aalter	[Opal] Buttgenbach, H. (1947) Les Minéraux de Belgique et du Congo belge. Dunod, Paris, 573 pages.; Mélon, J., Bourguignon, P., Fransolet, A.-M. (1976) Les minéraux de Belgique. Editions G. Lelotte, Dison (Belgique), 283 pages.; Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Flemish Brabant Linter ⓘ Wommersom	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Tienen	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Zaventem ⓘ Sint-Stevens-Woluwe	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Wallonia Hainaut Binche ⓘ Leval-Trahegnies	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Trahegnies	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Courcelles	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Fontaine-l'Évêque	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
La Louvière ⓘ Houdeng-Aimeries	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Strépy-Bracquegnies	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Canal work site	[Opal] Les minéraux de Belgique - Page 267 books.google.be/books?id=PncLAQAAIAAJ Joseph Mélon, ‎Pol Bourguignon, ‎André Mathieu Fransolet - 1976 - ‎Extraits -
Lens ⓘ Lens	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
ⓘ Montignies-lez-Lens	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Mons ⓘ Ciply	[Opal] http://natuurtijdschriften.nl/download?type=document&docid=566330
ⓘ Morlanwelz	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Liège Liège ⓘ Rocourt	[Opal] Fourmarier, P. (1901) Bois silicifié dans le sable de Rocourt. Annales de la Société géologique de Belgique, 29, B67.; Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Namur Namur ⓘ Vedrin	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Walloon Brabant ⓘ Court-Saint-Étienne	[Amber] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).
Walhain ⓘ Nil-Saint-Vincent-Saint-Martin	[Opal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French).

Bolivia
La Paz Aroma Province Sica Sica ⓘ Patacamaya	[Opal] Kempff, O., Paar, W.H., Tawackoli, S.: "Minerales de Bolivia", 115pp (La Paz, 2009)
Inquisivi Province Caracoles mining district ⓘ Caracoles Mine ?	[Opal] Kempff, O., Paar, W.H., Tawackoli, S.: "Minerales de Bolivia", 115pp (La Paz, 2009)
José Manuel Pando Province Berenguela mining district ⓘ San José de Berenguela Mine (Elisa Mine; Hucurani Mine)	[Opal] USGS Bulletin # 1975, p. 247.
Loayza Province Sapahaqui Caracato ⓘ Urmiri	[Opal-A var: Opal-AN] Ahlfeld, F. & Muñoz-Reyes, J. (1955) Las Especies Minerales de Bolivia
Oruro Carangas Province Todos Santos District ⓘ Carangas Mine (Orkho Thunko; Orcotunko)	[Opal] USGS Bulletin # 1975, p. 248.
Cercado Province Oruro ⓘ Iroco mine (Kori Chaka)	[Opal] USGS Bulletin # 1975, p. 269.
Pantaleón Dalence Province Huanuni ⓘ Cerro Pozokoni	[Opal] Federico Ahlfeld and Alejandro Schneider-Scherbina (1964) Los Yacimientos Minerales y de Hidrocarburos de Bolivia, Boletín No. 5 (Especial), page 170 (Ministerio de Minas y Petroleo, La Paz)
ⓘ Huanuni mine	[Opal] [MinRec 32:472]
ⓘ Quimsacoya mine	[Opal] Ahlfeld, F. & Schneider-Scherbina, A. (1964) Los Yacimientos Minerales y de Hidrocarburos de Bolivia.
Poopó Province ⓘ Poopó	[Opal] Salomon Rivas y Federico Ahlfeld (1998) Los Minerales de Bolivia y sus Parajes. (Santa Cruz)
Potosí Antonio Quijarro Province Tomave Municipality ⓘ Tolapampa 2	[Opal-A var: Opal-AN] Salomon Rivas y Federico Ahlfeld (1998) Los Minerales de Bolivia y sus Parajes. p. 535 (Santa Cruz)
Chayanta Province Macha area Condor Iquiña plateau ⓘ Huayoco	[Opal-A var: Opal-AN] Federico Ahlfeld and Jorge Muñoz Reyes (1955) Las Especies Minerales de Bolivia. (Banco Minero de Bolivia, 180 pp)
ⓘ Santiaguillo	[Opal-A var: Opal-AN] Federico Ahlfeld and Jorge Muñoz Reyes (1955) Las Especies Minerales de Bolivia. (Banco Minero de Bolivia, 180 pp)
Cornelio Saavedra Province Machacamarca mining district (Colavi mining district) ⓘ Canutillos subdistrict ?	[Opal] Pough, F. H. (1976) Peterson Field Guides - Rocks and Minerals, 4th Ed., plate 34.
Colavi subdistrict ⓘ Colavi Mine	[Opal] Ahlfeld & Munoz Reyes (1955): Las Especies Minerales de Bolivia
Daniel Campos Province San Pablo de Napa ⓘ El Desierto mine	[Opal-A var: Opal-AN] Alfredo Petrov collection
ⓘ San Pablo de Napa mine	[Opal] www.mineralmundi.com
Nor Lípez Province ⓘ Ollague Volcano	[Opal] www.mineralmundi.com (in the sulphur deposits)
Rafael Bustillo Province Llallagua ⓘ Siglo Veinte Mine	[Opal] Hyrsl, J. & A. Petrov (2006): Famous Mineral Localities: Llallagua, Bolivia. Mineralogical Record. 37: 117-162
ⓘ Uncía	[Opal] [MinRec 32:481]
Sud Lípez Province ⓘ Laguna Verde	[Opal] USGS Bulletin # 1975, p. 258 (1992)
ⓘ Rosario de Escala Mine (Escala Mine; Escala de Lipez Mine; Crosca Mine)	[Opal] Federico Ahlfeld and Alejandro Schneider-Scherbina (1964) Los Yacimientos Minerales y de Hidrocarburos de Bolivia. (Ministerio de Minas y Petroleo, La Paz)
San Antonio de Lípez ⓘ Machu Socavón Mine	[Opal] Geology and Mineral Resources of the Altiplano and Cordillera Occidental, Bolivia (USGS Bulletin no. 1975)
San Pablo de Lípez Santa Isabel district ⓘ Santa Isabel Mine (Candelaria Mine)	[Opal] Donald Richter, et al (1992) USGS Bulletin 1975, p.163.

Brazil	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (pp. 3, 70).

Bahia ⓘ Boa Nova	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70). Lv, Huiyu, and Ying Guo. (2023) "Genesis of the Body Color of Brazilian Gem-Quality Yellow-Green Opal" Crystals 13, no. 2: 316. https://doi.org/10.3390/cryst13020316
ⓘ Brejinho farm	[Opal] Cassedanne, J.P. and Cassedanne, J.O. (1977) Axinite, Hydromagnesite, Amethyst and Other Minerals from near Vitória da Conquista (Brazil). Mineralogical Record, 8(5), 382-387.
ⓘ Boquira	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Campo Formoso ultramafic complex	[Opal] F. Zaccarini, G. Garuti and R.F. Martin (2006): Exotic accessory minerals in layered chromitites of the Campo Formoso complex (Brazil). Geologica Acta 4, 461-469. [http://www.geologica-acta.com/pdf/vol0404a04.pdf]
Capim Grosso Pedras Altas ⓘ Pedras Altas claim	[Opal] Dutra, C. V., & Formoso, M. L. L. (2011). Considerações sobre os elementos terras raras em apatitas. Geochimica Brasiliensis, 9(2).
Gavião ⓘ Apolinário farm	[Opal] - Projeto Apatita, DNPM
Guajeru ⓘ Baixa da Braúna farm	[Opal-A var: Opal-AN] Mineralogical Record (1977) 8:382-387
Ipirá ⓘ Panelas farm	[Opal] - Projeto Apatita, DNPM
ⓘ Retiro farm	[Opal] - Projeto Apatita, DNPM
ⓘ Ipirá complex	[Opal] Projeto Apatita - DNPM
ⓘ Minas Gerais	[Opal] Martins da Pedra collection
Conselheiro Pena ⓘ Urucum claim	[Opal] Atencio D, Carvalho F M S, Matioli P A (2004) Coutinhoite, a new thorium uranyl silicate hydrate, from Urucum Mine, Galiléia, Minas Gerais, Brazil. American Mineralogist 89, 721-724
Coromandel Bagagem River valley Romaria ⓘ Romaria mine	[Opal] Chaves, M. L. S. C., and Svisero, D. P., 1993, Características geológicas e origem conglomerados diamantíferos das regiões de Diamantina (Mesoproterozóico) e de Romaria (Cretáceo Superior), Minas Gerais: Boletim Instituto Geociências, Univ.São Paulo, Séries Cient., v. 24, p. 49-57.
Galiléia Laranjeiras ⓘ Alto da Pitorra	[Opal-A var: Opal-AN] [MinRec 32:411]
Sapucaia do Norte ⓘ Sapucaia mine	[Opal-A var: Opal-AN] Cassedanne, J.P. & Baptista, A. (1999): Famous Mineral Localities: The Sapucaia Pegmatite Minas Gerais, Brazil. Mineralogical Record, 30: 347-360 + 365.
Itinga ⓘ Taquaral	[Opal-A var: Opal-AN] Luiz Menezes
Piauí valley ⓘ Guimarãesite occurrence	[Opal] Chukanov N V et al (2007) Guimarãesite, a new Zn-dominant monoclinic roscherite-group mineral from Itinga, Minas Gerais, Brazil, New Data on Minerals. Moscow, 42, 11-15
Pará São Geraldo do Araguaia ⓘ Manoel Ambrósio ranch	[Opal] Revista Brasileira de Geociências, vol.30
Paraíba Junco do Seridó ⓘ Alto Cajazeiras	[Opal] Pavel M. Kartashov analytical data, 2022
ⓘ Batalha mine	[Opal-A var: Opal-AN] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140. Carrino, T. A., Barreto, S. D. B., Oliveira, P. J. A. D., Araújo, J. F. D., & Correia, A. M. D. L. (2019). Linking gemology and spectral geology: a case study of elbaites from Seridó Pegmatite Province, Northeastern Brazil. Brazilian Journal of Geology, 49.
Vieirópolis Vieirópolis pegmatite field ⓘ Serra Branca amazonite pegmatite	[Opal-A var: Opal-AN] e Souza, B. D. A., Manoel, I., Guimarães, I. D. P., Barreto, S. D. B., Santos, G. L., & Araújo Neto, J. F. D. (2020). Whole-rock and mineral chemistry characterization of contrasting granitoids, constraints on the source of the Vieirópolis NYF-type pegmatites, Northeastern Brazil. Brazilian Journal of Geology, 50.
Paraná Foz do Iguaçu ⓘ Iguazu falls	[Opal] Geological Survey Professional Paper 327 (U.S. Department of the Interior, 1959)
ⓘ Piauí	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Buriti dos Montes	[Opal] Revista Escola de Minas 68 (2015) 53-59. Lv, Huiyu, and Ying Guo. (2023) "Genesis of the Body Color of Brazilian Gem-Quality Yellow-Green Opal" Crystals 13, no. 2: 316. https://doi.org/10.3390/cryst13020316
ⓘ Calçadinha farm	[Opal] Costa, M. L. D., Alencar, Q. D. S., Gomes, E. R., Almeida, H. D. F. D., & Oliveira, S. K. D. (2016). Textural patterns, mineralogy, and chemistry of sandstone-related Calçadinha chalcedony (Piauí, Brazil). Brazilian Journal of Geology, 46(3), 395-409.
ⓘ Pedro II	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (pp. 3, 68, 70-71). Lv, Huiyu, and Ying Guo. (2023) "Genesis of the Body Color of Brazilian Gem-Quality Yellow-Green Opal" Crystals 13, no. 2: 316. https://doi.org/10.3390/cryst13020316
ⓘ Barra	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Boi Morto mine	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (pp. 68-70).; de Brito Barreto, S. and Bretas Bittar, S.M. (2010) Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Bom Lugar	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Cantinho	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Centro	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Chã do Lambedor	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Corrente creek	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Limão	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Mamoeiro	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).; de Brito Barreto, S. and Bretas Bittar, S.M. (2010) Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Morro do Meio	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Pajeu	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Pirapora	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Rio dos Matos	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Roça mine	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Rio Grande do Norte	[Opal] No reference listed
Bodó ⓘ Bodó Mine	[Opal] de Hollanda, M. H. B., Neto, J. A. S., Archanjo, C. J., Stein, H., & Maia, A. C. (2017). Age of the granitic magmatism and the W-Mo mineralization in skarns of the Serido belt (NE Brazil) based on zircon U-Pb (SHRIMP) and molybdenite Re-Os dating. Journal of South American Earth Sciences, 79, 1-11.
ⓘ Currais Novos	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Lajes Pintadas	[Opal]
Parelhas ⓘ Capoeira 1 pegmatite (Boqueirãozinho pegmatite)	[Opal-A var: Opal-AN] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
ⓘ Capoeira 2 pegmatite (Mulungu pegmatite)	[Opal] de Brito Barreto, S., & Bretas Bittar, S. M. (2010). Los depósitos de gemas de Brasil: localización, producción e impacto económico. Boletín de la Sociedad Geológica Mexicana, 62(1), 123-140.
Rio Grande do Sul ⓘ Campos Borges	[Opal] www.gemstone.org/gem-by-gem/english/fire.html
Caxias do Sul ⓘ Monte Bérico	[Opal] Fernando Brederodes Collection
Estância Velha ⓘ Incopel quarry	[Opal] Frank, H.T. (2008) Gênese e padrões de distribuição de minerais secundários na formação Serra Geral (Bacia do Paraná). [Genesis and patterns of secondary minerals distribution in the Serra Geral formation (Bacia do Parana)]. PhD thesis (Geosciences) Universidade Federal do Rio Grande do Sul, Brazil.
ⓘ Lajeado	[Opal] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (p. 70).
ⓘ Salto do Jacuí	[Opal] Strieder, A. J., & Heemann, R. (2006). Structural constraints on Paraná basalt volcanism and their implications on agate geode mineralization (Salto do Jacuí, RS, Brazil). Pesquisas em Geociências. Porto Alegre, RS. Vol. 33, n. 1 (2006), p. 37-50.
Rondônia Porto Velho ⓘ Amazon Opal Mine	[Opal]
Santa Catarina ⓘ Tangará	[Opal-A var: Opal-AN] Manfred Bergmann (2009) Lapis, 34, #3, 30-34.
ⓘ São Paulo	[Opal] Revista Brasileira de Geociências 27:395-402
São Paulo ⓘ Perus	[Opal] American Mineralogist 54:966-969; D Atencio & R Hypolito ()Fosfatos e silicatos secunderos de uranio de Perus, Sao Paulo
ⓘ Pegmatite quarries	[Opal] Fosfatos e Silicatos Secundários de Urânio de Perus, São Paulo - Atencio, Daniel and Hypolito, Raphael - Revista Brasileira de Geociências, março de 1994
Serrana ⓘ Serrana basalt quarry	[Opal-A var: Opal-AN] Ruiz, M. (2001) Zeólitas em amígdalas do basalto das cidades de Araraquara e Serrana-São Paulo. Ph.D. Thesis, São Paulo State University, Institute of Chemistry, São Paulo, 89 pp. + 63 pp. (appendix).

Bulgaria
Dobrich Province Balchik Municipality Obrochishte ⓘ Obrochishte deposit	[Opal] Aleksiev, B. (1967): Barite in manganese ore deposits of Obrochishte. Doklady Bolgarskoi Akademii Nauk 20(10), 1053-1055 (in Russian).
Haskovo Province Madzharovo Municipality Madzharovo ⓘ Madzharovo deposit	[Opal] Marchev, P., Downes, H., Thirlwall, M. F., & Moritz, R. (2002). Small-scale variations of 87Sr/86Sr isotope composition of barite in the Madjarovo low-sulphidation epithermal system, SE Bulgaria: implications for sources of Sr, fluid fluxes and pathways of the ore-forming fluids. Mineralium Deposita, 37(6-7), 669-677.
Mineralni Bani Municipality ⓘ Mineralni Bani sandpit	[Opal] Marcus Voigt Collection
ⓘ Tatarevo	[Opal-A var: Opal-AN] Marcus Voigt Collection
ⓘ Kardzhali Province	[Opal] www.clmc.bas.bg/Annreps/ANNREP8/annrep8.htm.
Kardzhali Municipality Beli Plast ⓘ Beli Plast complex	[Opal] Dimowa, Louiza, Nadia Petrova, Yana Tzvetanova, Ognyan Petrov, and Iskra Piroeva. (2022) "Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria)" Minerals 12, no. 12: 1576. https://doi.org/10.3390/min12121576
ⓘ Krumovgrad Municipality	[Opal] http://www.clmc.bas.bg/Annreps/ANNREP8/annrep8.htm
ⓘ Ada Tepe Au deposit	[Opal] Marchev, P.; Singer, B. S.; Jelev, D.; Hasson, S.; Moritz, R.; Bonev, N. (2004): The Ada Tepe deposit: a sediment-hosted, detachment fault-controlled, low-sulfidation gold deposit in the Eastern Rhodopes, SE Bulgaria. Swiss Bulletin of Mineralogy and Petrology, 84, 2004, 59-78. ; Marinova, I. (2008). Morphology of electrum from Khan Krum gold deposit, Krumovgrad goldfield, Eastern Rhodope Mountain, SE Bulgaria. Geologica Macedonica, 2, 111-120.
ⓘ Potochnitsa	[Opal] http://www.clmc.bas.bg/Annreps/ANNREP8/annrep8.htm
ⓘ Studen kladenets	[Opal] Anton Ivanov field observation
Momchilgrad Municipality ⓘ Zvezdel	[Opal] Tschernich, 1992. Zeolites of the World
ⓘ Dachiardite-K occurrence	[Opal] Encheva, S., Petrov, P., Chukanov, N., Pekov, I., Енчева, С., Петко, П., ... & Пеков, И. Dachiardite-K from the area of Austa village, Momchilgrad municipality, Eastern Rhodopes–a new mineral species of zeolite group Дакиардит-K от района на с. Ауста, община Момчилград, Източни Родопи–нов минерален вид от групата на зеолитите.
Pazardzhik Province Rakitovo Municipality ⓘ Dorkovo	[Opal] Marcus Voigt Collection
Sofia City Province Stolichna Municipality ⓘ Lozen	[Opal] I. Kostov, V. Breskovska, J. Mincheva-Stefanova, G. Kirov (1964): Minerals of Bulgaria. Sofia, Bulgaria, 540 pp. (in Bulgarian).
Yambol Province Tundzha Municipality Krumovo ⓘ Krumovo iron mine	[Opal] Marcus Vau Collection

Cambodia
Kampong Thom Province ⓘ Phnom Chi 2 (Chi Mountain)	[Opal-A var: Opal-AN] Economic and Social Commission for Asia and the Pacific (1993) Atlas of Mineral Resources for the Escap Region Cambodia Vol 10 UN.
ⓘ Ratanakiri Province	[Opal] Austin, Gordon et al. "World Mining Report". Colored Stone (November–December 2005).
Stung Treng Province Khone district ⓘ Preah Angkol	[Opal-A var: Opal-AN] Economic and Social Commission for Asia and the Pacific (1993) Atlas of Mineral Resources for the Escap Region Cambodia Vol 10 UN.
Takeo Province Kirivong ⓘ Phnom Bayong	[Opal] Piilonen, P., Lykova, I., Poirier, G., Rowe, R., Bainbridge, M., Shepherd, K. & Ly., S. (2022): The mineralogy of the gem-bearing pegmatites and hydrothermal veins at Phnom Bayong, Kirivong, Takeo province, Cambodia. Rocks & Minerals. (submitted).

Cameroon
South Region Dja-Et-Lobo Meyomessi ⓘ Mezesse	[Opal] Willems, L., Compère, P., Hatert, F., Pouclet, A., Vicat, J. P., Ek, C., & Boulvain, F. (2002). Karst in granitic rocks, South Cameroon: cave genesis and silica and taranakite speleothems. Terra Nova, 14(5), 355-362.

Canada
ⓘ Alberta	[Amber] www.alpinegems.net
Peace River ⓘ Clear Hills	[Opal] Bertram, E. F., & Mellon, G. B. (1975). Peace River iron deposits (Vol. 75). Alberta Research Council.; Petruk, W., Farrell, D. M., Laufer, E. E., Tremblay, R. J., & Manning, P. G. (1977). Nontronite and ferruginous opal from the Peace River iron deposit in Alberta, Canada. The Canadian Mineralogist, 15(1), 14-21.
British Columbia Atlin Mining Division Nahlin River area ⓘ Nahlin River Ni-Cu occurrence	[Opal] personal correspondence with Giles Peatfield
ⓘ Opal Lake Ni-Cu occurrence	[Opal] personal correspondence with Giles Peatfield
Kamloops Mining Division Bonaparte River Area ⓘ Scottie Creek Cr prospect	[Opal] personal correspondence with Giles Peatfield ( see notes on minerals in description)
Mt. Savona Deadman's River ⓘ Pass Valley	[Opal] Tschernich - Zeolites of the World (1992)
Omineca Mining Division Burns Lake ⓘ Eagle Creek	[Opal] www.em.gov.bc.ca/cf/minfile
ⓘ Firestorm prospect	[Opal] Wojdak, P. 2002. Firestorm: precious opal related to rhyolite ignimbrite. BC Ministry of Energy, Mines, and Resources, Exploration and Mining in BC - 2001, p. 97-100.
Whitesail Range Troitsa Peak ⓘ Northern Lights claims	[Opal] MINFILE No 093E 120
Similkameen Mining Division ⓘ Coalmont	[Amber] Mustoe, G. E. (1985). Eocene amber from the Pacific coast of North America. Geological Society of America Bulletin, 96(12), 1530-1536
ⓘ Princeton	[Amber] Simandl, G.J. (2009): Nonmetallic minerals other than coal: Industrial minerals, gemstones and aggregate in British Columbia, Canada; British Columbia Geological Survey, Paper 2009‐2, pages.
Vancouver Island Alberni Mining Division ⓘ Catface Cu-Mo deposit	[Opal] Minfile Database (2017)
Vernon Mining Division Vernon ⓘ Klinker prospect	[Opal] www.em.gov.bc.ca/cf/minfile; Simandl, G. J., Hancock, K. D., Callaghan, B., Paradis, S., & Yorke-Hardy, R. (1997). Klinker Precious Opal Deposit, South Central British Columbia, Canada-Field Observations and Potential Deposit-Scale Controls. British Columbia Ministry of Energy and Mines, 321-327.
Manitoba ⓘ Cedar Lake	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.; George O. Poinar (1992) Life in Amber. (Stanford University Press)
Souris ⓘ Souris gravel pit	[Opal] John Sinkankas (1959) Gemstones of North America: Volume 3; Phillips, K. A. (1978) Minerals of Manitoba: Vol 1 Nonmetallic and pegmatic. Manitoba Mineral Resources Division Educational Series 78/1.
Newfoundland and Labrador Newfoundland Placentia Bay ⓘ La Manche	[Opal] White, Jason (2015) La Manche Pb-Zn-Ag-REE's. Poster.
Northwest Territories ⓘ O'Grady Lake area	[Opal] Canadian Mineralogist 41:117-137
Nova Scotia Cumberland Co. ⓘ McKay Head	[Opal] J.N. Wingard.
Lunenburg Co. ⓘ New Ross	[Opal] H. Piers, "The Occurrence of Opal in Granite near New Ross, Lunenburg County, N.S.", Proceedings of the Nova Scotian Institute of Science, vol. 12, pt. 4, 446-449, 1910.
Ontario Hastings County Town of Bancroft Dungannon Township York River area ⓘ Golding-Keene Quarry (Goulding-Keene) ?	[Opal] Michael Adamowicz Collection
Kawartha Lakes ⓘ Norland area (Shadow Lake area)	[Opal] Shadow Lake RockHounders Facebook group
Renfrew County Lyndoch and Raglan Brudenell Lyndoch Township ⓘ Beryl Pit	[Opal] www.ontariominerals.com/berylpit.htm
Québec Abitibi-Témiscamingue Témiscamingue RCM Les Lacs-du-Témiscamingue ⓘ Kipawa alkaline complex	[Opal] Ansell H G, Roberts A C, Plant A G, Sturman B D (1980) Gittinsite, a new calcium zirconium silicate from the Kipawa agpaitic syenite complex, Quebec, The Canadian Mineralogist 18, 201-203
Montérégie La Vallée-du-Richelieu RCM Mont Saint-Hilaire ⓘ Poudrette quarry (De-Mix quarry; Demix quarry; Uni-Mix quarry; Carrière Mont Saint-Hilaire; MSH)	[Opal] http://membres.lycos.fr/quebecminerals/tripbluequartz.html
Lajemmerais RCM Varennes & St-Amable ⓘ Saint-Amable sill	[Opal] HORVÁTH, L., PFENNINGER HORVÁTH, E., GAULT, R.A., and TARASSOFF, P. (1998) Mineralogy of the Saint Amable sill, Varennes and Saint Amable, Québec, Canada. Mineralogical Record, 29, 83 118.
ⓘ Demix-Varennes quarry	[Opal] Horváth, L., Pfenninger-Horváth, E., Gault, R. A., & Tarassoff, P. (1998): Mineralogy of the Saint-Amable Sill, Varennes and Saint-Amable, Québec. Mineralogical Record, 29: 83-118.
Yukon Dawson mining district ⓘ Clinton Creek Mine	[Opal] Sabina, A.P. (1972) Rocks & minerals for the collector: The Alaska Highway, Dawson Creek, British Columbia to Yukon/Alaska border. GSC paper 72-32. Reissued (1992) as GSC Miscellaneous Report 50, 98-99.

Cape Verde
Sotavento Islands ⓘ Santiago Island	[Opal] M.M.S. Cabral Pinto, M.M.V. Silva,R. Hernandez and E.A. Ferreira Da Silva (2011) Mineralogy of stream sediments and soils of Santiago Island, Cape Verde. Goldschmidt Conference Abstracts. Mineralogical Magazine 75:610

Chile
Antofagasta Antofagasta Province Mejillones Mejillones peninsula ⓘ Cerro Mejillones	[Opal] http://www.handbookofmineralogy.com/pdfs/mejillonesite.pdf; Atencio, D., Chukanov, N. V., Nestola, F., Witzke, T., Coutinho, J. M., Zadov, A. E., ... & Färber, G. (2012). Mejillonesite, a new acid sodium, magnesium phosphate mineral, from Mejillones, Antofagasta, Chile. American Mineralogist, 97(1), 19-25.
Sierra Gorda ⓘ Alcaparrosa Mine	[Opal] Chukanov, N.V., Aksenov, S.M., Rastsvetaeva, R.K., Möhn, G., Rusakov, V.S., Pekov, I.V., Scholz, R., Eremina, T.A., Belakovskiy, D.I. and Lorenz, J.A. (2016): Magnesiovoltaite K2Mg5Fe3+3Al(SO4)12•18H2O, a new mineral from the Alcaparrosa mine, Antofagasta region, Chile. European Journal of Mineralogy, 28, 1005-1017
Caracoles mining district Caracoles ⓘ Los Tres Presidentes Mine	[Opal] R. S. W. Braithwaite et al.: Mineralogical Magazine 68(3):527-539 (2004)
El Loa Province Calama Chuquicamata District ⓘ Chuquicamata Mine	[Opal] Cook, R.B. (1978) Famous mineral localities: Chuquicamata, Chile. The Mineralogical Record: 9(5): 321-333.
ⓘ El Tatio geothermal field	[Opal] Rodgers, K. A., Greatrex, R., Hyland, M., Simmons, S. F., & Browne, P. R. L. (2002). A modern, evaporitic occurrence of teruggite, Ca4MgB12As2O28. 18H2O, and nobleite, CaB6O10. 4H2O, from the El Tatio geothermal field, Antofagasta Province, Chile. Mineralogical Magazine, 66(2), 253-259.; TESIS PARA OPTAR AL GRADO DE MAGÍSTER EN CIENCIAS, MENCIÓN GEOLOGÍA MEMORIA PARA OPTAR AL TÍTULO DE GEÓLOGO CONSTANZA BEATRIZ NICOLAU DEL ROURE EYLERTS, 2013
Ollagüe ⓘ Cerro Pabellón Geothermal System	[Opal] Vidal, Jeanne, Patricia Patrier, Daniel Beaufort, Santiago Maza, Germain Rivera, Gianni Volpi, and Diego Morata. (2022) "Clay Minerals in the Deep Reservoir of the Cerro Pabellón Geothermal System (Northern Chile)" Minerals 12, no. 10: 1244. https://doi.org/10.3390/min12101244 Vidal, Jeanne, Patricia Patrier, Daniel Beaufort, Santiago Maza, Germain Rivera, Gianni Volpi, and Diego Morata. (2022) "Clay Minerals in the Deep Reservoir of the Cerro Pabellón Geothermal System (Northern Chile)" Minerals 12, no. 10: 1244. https://doi.org/10.3390/min12101244
Tocopilla Province Tocopilla ⓘ Santa Ana Mine (Chapacase Mine)	[Opal] samples analysed by Gerhard Mohn and Joy Desor
Araucanía Cautín Province ⓘ Alpehue geyser field	[Opal] Munoz-Saez, C., Perez-Nuñez, C., Martini, S., Vargas-Barrera, A., Reich, M., Morata, D., & Manga, M. (2020). The Alpehue geyser field, Sollipulli Volcano, Chile. Journal of Volcanology and Geothermal Research, 406, 107065.
Atacama Copiapó Province Copiapó Cachiyuyo de Llampos mining district Carrera Pinto ⓘ San Samuel Mine ("San Manuel Mine")	[Opal] samples analysed by Gerhard Mohn and Joy Desor
ⓘ Capitana Mine	[Opal] samples analysed by Gerhard Moehn
Quebrada San Miguel ⓘ Los Azules mine	[Opal] samples analysed by Jochen Schluter, Gerhard Mohn and Joy Desor
ⓘ Soledad mine	[Opal] Sernageomin database 2005;Stgo de Chile
Tierra Amarilla Las Pintadas mining district Cerro Pintado ⓘ La Farola Mine	[Opal] samples analysed by Gerhard Mohn and Joy Desor
Pampa Larga mining district ⓘ Jote Mine	[Opal] Samples analysed by Dr. Tony Kampf, Curator of LAC Mineralogical Museum, USA; Kampf, A. R., Mills, S. J., Housley, R. M., Rossman, G. R., Nash, B. P., Dini, M., & Jenkins, R. A. (2013). Joteite, Ca2CuAl [AsO4][AsO3 (OH)] 2 (OH) 2· 5H2O, a new arsenate with a sheet structure and unconnected acid arsenate groups. Mineralogical Magazine, 77(6), 2811-2823.; Kampf, A. R., Mills, S. J., Nash, B. P., Dini, M., & Molina Donoso, A. A. (2015). Tapiaite, Ca5Al2 (AsO4) 4 (OH) 4· 12H2O, a new mineral from the Jote mine, Tierra Amarilla, Chile. Mineralogical Magazine, 79(2), 345-354.
ⓘ Veta Negra Mine	[Opal] samples analysed by Gerhard Mohn and Joy Desor
Huasco Province Alto del Carmen ⓘ Pascua Lama project	[Opal] Economic Geology; January 2005; v. 100; no. 1; p. 131-148 Chouinard, A., Williams-Jones, A.E., Leonardson, R.W., Hodgson, C.J., Silva, P., Téllez, C, Vega, J., and Rojas, F. (2005): Geology and genesis of the multistage high-sulfidation epithermal Pascua Au-Ag-Cu deposit, Chile and Argentina. Econonic Geology, 100, 463–490.
Coquimbo Elqui Province El Indio deposit ⓘ Canto Sur Mine (Indio Sur vein)	[Opal] Jannas R./Araneda R.; "Geología de la veta Indio Sur; una estructura tipo Bonanza del yacimiento El Indio"; Revista Geológica Chilena, 1985, Stgo de Chile.
Tarapacá Tamarugal Province Huara ⓘ Patricia deposit	[Opal] Darío Chinchilla, Lorena Ortega, Rubén Piña, Raúl Merinero, Daniel Moncada, Robert J. Bodnar, Cecilio Quesada, Antonio Valverde, Rosario Lunar (2016): The Patricia Zn–Pb–Ag epithermal ore deposit: An uncommon type of mineralization in northeastern Chile. Ore Geology Reviews 73, 104-126.
Valparaíso Los Andes Province ⓘ Vizcachitas property	[Opal-A var: Opal-AN] Tetra Tech Chile (2019) Preliminary Economic Assessment

China
Anhui Anqing Huaining County ⓘ Bailing Au deposit	[Opal] Wenya Zhou and Deming Xu (1990): Acta Petrologica et Mineralogica 9(1), 69-77
Chizhou Qingyang Co. ⓘ Shimenkou Cu-Au-S-Fe deposit (Zhimenkou Cu-Au-S-Fe deposit)	[Opal] Yuanming Pan and Ping Dong (1999): Ore Geology Reviews 15, 177-242.
Chuzhou Quanjiao County ⓘ Quanjiao sepiolite deposit	[Opal] Pan Fang, Fahui Pan, and Qichai He (1981): Acta Mineralogica Sinica 3(1), 73-77; Wenguang Li (1997): Jilin Geology 16(4), 22-25; Ruishi Yang and Wenguang Li (2001): Geology of Chemical Minerals 23(1), 25-30
Wuhu Fanchang County ⓘ Xiaoyangchong deposit	[Opal] Zhang, Songsong, Xiaoyong Yang, and Lei Liu. (2023) "Evolution, Magmatic Source and Metallogenesis of A-Type Granites in the Fanchang Volcanic Basin, Middle and Lower Yangtze Metallogenic Belt: A Review" Minerals 13, no. 4: 571. https://doi.org/10.3390/min13040571
Nanling County ⓘ Yaojialing Zn-Au deposit	[Opal] Chunhua Wen, Wenyi Xu, Hong Zhong, Qingtian Lü, Zhusen Yang, Shihong Tian, and Yingchao Liu (2011): Mineral Deposits 30(3), 533-546
Xuancheng Jixi Co. ⓘ Ladaling U deposit	[Opal] National Geological Archives of China database, record no. X00038564
Chongqing Chengkou Co. ⓘ Gaoyan Mn deposit	[Opal] Gongqin Zhang (1986): Geology and Prospecting 22(7), 10-16
Fujian Longyan Liancheng Co. Liancheng Mn deposit ⓘ Lanqiao Mine	[Opal] Nanlai Zheng, Xingli Mao, and Jiansheng Ding (1986): Geology and Prospecting 22(3), 17-20; Huacai Chen (1989): Geology and Prospecting 25(10), 6-11
Shanghang Co. Zijinshan ore field ⓘ Zijinshan Mine	[Opal] http://pubs.usgs.gov/of/2005/1060/PorCu.txt
Ningde Zhouning Co. ⓘ Qinxi-Guansi Ag-Pb-Zn deposit	[Opal] Yachui Jiang, Henian Chen, Cuanhuai Wu, and Shizhong Chen (1994): Geology and Prospecting 30(4), 21-25
Zhangzhou Yunxiao Co. Tongbei ⓘ Wushan Spessartine Mine	[Opal-A var: Opal-AN] C. Lemanski, Jr. and Ottens, B., 2005. Tongbei. Spessartine localities, Fujian Province, China. Mineralogical Record, 36 (1): 35-43
Gansu Gannan Diebu Co. (Têwo Co.) ⓘ Luoda U deposit	[Opal] National Geological Archives of China database, record no. X00043161
Jiuquan Guazhou Co. ⓘ Shuangjingzi Fe deposit	[Opal] Laigeng Yang (1989): Geology and Prospecting 25(6), 9-13
Subei Co. ⓘ Nanjinshan Mine	[Opal] Yuanchao Shen, Ping Shen, Qingdong Zeng, Tiebing Liu, and Guangming Li (2006): Mineral Deposits 25(5), 572-581; Shen Ping, Shen Yuanchao, Liu Tiebing, Li Guangming, and Zeng Qingdong (2008): Mineralium Deposita 43(5), 499-517
Guangdong Heyuan Zijin Co. ⓘ Tiezhang Sn deposit	[Opal] Gongsheng Yan (1987): Mineral Deposits 6(1), 45-55
Shaoguan Nanxiong Co. ⓘ Zoumalian	[Opal] Liangshu Shu, Ping Deng, Bin Wang, Zhengzhong Tan, Xinqi Yu, and Yan Sun (2004): Science in China, Series D (Earth Sciences), 47(8), 673-688.
Shixing Co. ⓘ Diaodangpai zeolite occurrence	[Opal] Liangshu Shu, Ping Deng, Bin Wang, Zhengzhong Tan, Xinqi Yu, and Yan Sun (2004): Science in China, Series D (Earth Sciences), 47(8), 673-688.
Wengyuan Co. ⓘ Xiazhuang Uranium ore field (Xiwang Uranium ore field)	[Opal] Dahlkamp, F.J., Ed. (2009): Uranium Deposits of the World. Springer (Berlin, Heidelberg), pp. 31-156.
Guangxi Chongzuo Daxin Co. ⓘ Daxin Mine (Saqisan Mine; Sanqisan Mine; U deposit No. 373)	[Opal] Min, M.-Z., Luo, X.-Z., Mao, S.-L., Zheng, D.-Y., and Shen, B.-P. (2002): Ore Geology Reviews 19(1/2), 79-93.
Guizhou Qianxinan Qinglong County ⓘ Wangjiawan Au deposit	[Opal] Yongzhi Zhang and Maorong Zhen (2004): Guizhou Geology 21(2), 99-105
Hainan Changjiang Co. ⓘ Shilu Mine	[Opal] Hanzhu Wang (1985): Earth Science, Journal of China University of Geosciences 29(2)
Paracel Islands ⓘ Chenhang Island	[Opal] Zhang, Yu, Kefu Yu, and Handong Qian. (2018) "LA-ICP-MS Analysis of Clinopyroxenes in Basaltic Pyroclastic Rocks from the Xisha Islands, Northwestern South China Sea" Minerals 8, no. 12: 575. https://doi.org/10.3390/min8120575
Hebei Handan Wu'an County ⓘ Yingli Au deposit	[Opal] Guilin Xu, Xiaolan Shi, and Hongcai Xu (2006): Geology and Prospecting 42(2), 13-18
Qinhuangdao Qinglong County ⓘ Xiazhangzhi Au deposit	[Opal] http://wrgis.wr.usgs.gov/open-file/of03-220/DATABASE/lode_deposits.txt
Heilongjiang Daxing'anling Tahe County ⓘ Shiwuliqiao Au deposit	[Opal] Xiangwen Li, Yanchen Yang, Songqing Ye, Zhijie Liu, Changlai Shao, and Haifeng Wai (2014): Geology and Exploration 50(1), 77-87
Heihe Xunke County ⓘ Gaosongshan Au deposit	[Opal] Zhong Tang, Songqing Ye, and Yanchen Yang (2010): Global Geology 29(3), 400-407
Jixi Hulin City ⓘ Sipingshan Au deposit	[Opal] Yongwei Huang, Guanghui Li, and Dachao Lu (2010): Global Geology 29(2), 226-233
ⓘ Xianfengbeishan Au deposit	[Opal] Jianguo Yang, Chuanshun Quan, and Xiuli Liu (2005): Gold Science and Technology 13(5), 26-29
Yichun Jiayin County Wulaga Mine ⓘ Tuanjiegou Au deposit	[Opal] http://www.portergeo.com.au/database/mineinfo.asp?mineid=mn1061; Guihu Chen, Fuzhou Wang, Yanzhong Wang, Jiguang Xue, Cangjiang Zhang, Yajun Li, and Xiaojun Duan (2012): Gold Science and Technology 20(2), 14-19
Henan Luoyang Luanchuan County Nannihu ore field ⓘ Nannihu-Sandaozhuang Mine	[Opal] Jichang Weng, Yunzheng Zhang, Chaoyong Huang, Wenzhi Li, Beilei Cui, and Mingwei Luo (2010): Geology and Exploration 46(1), 41-48
Nanyang ⓘ Xixia County	[Amber] Huishu Wang (1989): Acta Mineralogica Sinica 9(4), 338-344
Sanmenxia Lingbao City ⓘ Yinjiagou polymetallic deposit	[Opal] Guang Wu, Yuchuan Chen, Zongyan Li, Xinsheng Yang, Jun Liu, and Cuijie Qiao (2013): Mineral Deposits 32(4), 809-822
Hong Kong New Territories Sha Tin District Ma On Mountain (Ma On Shan) ⓘ Ma On Shan Mine	[Opal] Li, X.C. (2008) Hong Kong Geology Guide Book. Geotechnical Engineering Office, Civil Engineering and Development Department, Government of the Hong Kong
Hunan Loudi Lengshuijiang Co. ⓘ Xikuangshan Sb deposit (Xikuangshan antimony deposit)	[Opal] Guozhang Wen, Qiang Wu, Hanyuan Liu, Guozhu Xie, and Xiuliu Lei (1993): Geology and Prospecting 29(7), 20-27
Shaoyang Shaodong Co. ⓘ Lushan'ao Mn deposit	[Opal] Ziqiang Wei (1976): Geology and Prospecting 12(8), 25-29
ⓘ Unnamed U deposit (1)	[Opal] Hunan 230 Laboratory, Hunan 305 Geological Team, Wuhan Geological Institution X-ray Laboratory (1976): Acta Geologica Sinica 50(2), 203-204.
Xiangtan Yuhu District ⓘ Heling Mn deposit	[Opal] Ziqiang Wei (1976): Geology and Prospecting 12(8), 25-29
Yiyang Heshan District ⓘ Tangganshan Mine	[Opal] Ziqiang Wei (1976): Geology and Prospecting 12(8), 25-29
Zhuzhou ⓘ Xiaojiashan Au deposit	[Opal] Hou, Dongzhuang, Shu Lin, Lang Liu, Chao Huan, Huafu Qiu, and Bingbing Tu. (2023) "Metal Source and Fluid Evolution in Xiaojiashan Gold Deposit in Northeastern Hunan, China: Implications of Rare Earth Elements, Fluid Inclusions, and Pyrite S Isotopic Compositions" Minerals 13, no. 1: 121. https://doi.org/10.3390/min13010121
Inner Mongolia Alxa League (Alashan Prefecture) Ejin Banner (Ejina Co.) ⓘ Laodonggou Mine	[Opal] Dianhao Huang and Baolin Wang (1997): Journal of Precious Metallic Geology 6(2), 93-100
Baotou City (Baotou Prefecture) Bayan Obo mining district Bayan Obo ⓘ Bayan Obo deposit	[Opal] Qingchang Meng (1981): Geology and Prospecting 17(3), 10-17
Bayannur City (Bayannao'er Prefecture) Urad Rear Banner (Wulate Houqi) ⓘ Dongshengmiao Mine	[Opal] Zhaolong Li, Wendou Xu, Yijie Xi, and Xinming Jiang (1981): Geology and Prospecting 17(6), 7-14
ⓘ Tanyaokou Fe-Cu-Zn deposit	[Opal] Zhaolong Li, Wendou Xu, Yijie Xi, and Xinming Jiang (1981): Geology and Prospecting 17(6), 7-14
Chifeng City (Ulanhad League; Chifeng Prefecture) Bairin Left Banner (Balin Zuoqi) ⓘ Tuofengshan Cu-Fe deposit	[Opal] Tai Zhang and Yunji Liu (2002): Geology of Chemical Minerals 24(1), 39-47
Hinggan League (Xing'an Prefecture) Tuquan County ⓘ Lianhuashan Mine	[Opal] Lingan Bai, Jinggui Sun, Qinglong Sun, Alei Gu, Keqiang Zhao, and Lanjing Men (2012): Mineral Deposits 31(6), 1249-1258
Hulunbuir City (Hulunbei'er Prefecture) Ergun City (E'erguna Co.) ⓘ Sanhe Pb-Zn deposit	[Opal] Liu, J., He, J. C., Lai, C. K., Pan, J. Y., & Wang, X. T. (2022). The Middle Jurassic Sanhe Pb–Zn–Ag deposit in NE China: Constraints from Geochronology, Geochemistry, Fluid Inclusion and Multi-Isotope (S–Pb–He–Hf) Systematics. Ore Geology Reviews, 105181.
Genhe ⓘ Biliya deposit	[Opal] Xu, Z. K., Sun, J. G., Xu, Z. T., Mei, Y. X., & Liang, X. L. (2022). Fluid inclusion and isotopic constraints on the origin of the Ag-Pb-Zn polymetallic mineralization at Biliya, Great Xingan Range, NE China. Ore Geology Reviews, 104793.
ⓘ Erdaohezi Pb-Zn deposit	[Opal] Xu, Z.; Sun, J.; Liang, X.; Xu, Z.; Chu, X. (2020) Geochronology, Geochemistry, and Pb–Hf Isotopic Composition of Mineralization-Related Magmatic Rocks in the Erdaohezi Pb–Zn Polymetallic Deposit, Great Xing’an Range, Northeast China. Minerals 10, 274.
Old Barag Banner (Chenba'erhu Co.) ⓘ Xie'ertala Mine	[Opal] Feng Yuan, Degao Zhai, Jiajun Liu, Xiaodong Mao, Jianping Wang, Lidong Liu, Huailing Ma, Shouguang Wang, and Yuxi Li (2012): Geological Bulletin of China 31(6), 954-968
Ulanqab City (Wulanchabu Prefecture) Dorbod Banner (Siziwang Co.) ⓘ Sumt Qagan Obo Mine (Sumo Qagan Obo Mine; Sumo Chagan Aobao Mine)	[Opal] Fengjun Nie, Dongqin Xu, Sihong Jiang, and Yan Liu (2008): Mineral Deposits 27(1), 1-13
Xilingol League (Xilinguole Prefecture) ⓘ Wuliji’Oboo deposit	[Opal] Zou, H., Pei, Q. M., Li, X. Y., Zhang, S. T., Ware, B., Zhang, Q., ... & Yu, H. D. (2022). Application of field-portable geophysical and geochemical methods for tracing the Mesozoic-Cenozoic vein-type fluorite deposits in shallow overburden areas: a case from the Wuliji'Oboo deposit, Inner Mongolia, NE China. Ore Geology Reviews, 104685.
Jiangsu Huai'an Xuyi Co. ⓘ Huangnishan clay deposit	[Opal] Tianhu Chen, Xiaochun Xu, Shucang Yue, and Jinzhong Li (2002): Geology and Prospecting 38(2), 49-54; Tianhu Chen, Huifang Xu, Anhuai Lu, Shuchuan Peng, and Shucang Yue (2004): Science in China, Series D (Earth Sciences), 47(11), 985-1004
ⓘ Yongxiaoshan sepiolite deposit	[Opal] Wenguang Li (1997): Jilin Geology 16(4), 22-25; Ruishi Yang and Wenguang Li (2001): Geology of Chemical Minerals 23(1), 25-30
Suzhou Huqiu District ⓘ Suzhou china clay deposit	[Opal] Kecong Han and Shengyun Ma (1985): Mineral Deposits 4(2), 58-68
Jiangxi Ganzhou Ruijin Co. ⓘ Xiefang Mine	[Opal] Yunhuai Lin (1986): Geology and Prospecting 22(4), 22-28
Jiujiang Xiushui Co. Xiushui Uranium ore field ⓘ Baitou U deposit (Baiti U deposit)	[Opal] Dahlkamp, F.J., Ed. (2009): Uranium Deposits of the World. Springer (Berlin, Heidelberg), pp. 31-156
ⓘ Baofengyuan U deposit (Baoyan U deposit)	[Opal] Dahlkamp, F.J., Ed. (2009): Uranium Deposits of the World. Springer (Berlin, Heidelberg), pp. 31-156
Jilin Baishan Fusong County ⓘ Lushuihe Mine	[Opal] Jie Yao, Honglin Yu, Anping Wang, and Yixing He (2002): Journal of Jilin University (Earth Science Edition) 32(1), 43-50
Jiangyuan District (Hunjiang Co.) ⓘ Xiaoshiren Au deposit	[Opal] Shiyuan Wang, Jizhang Fan, Yajian Liu, and Shan Xu (2007): Geological Bulletin of China 26(7), 909-915
Jilin Huadian City Jiapigou ore field ⓘ Wangjiadian Mine	[Opal] Bin Kang, Jirong Bo, and Diguang Dong (2000): Geology and Prospecting 36(6), 27-31
Yanbian Chaoxianzu Wangqing County ⓘ Jiusangou Au deposit (Jiushisangou Au deposit)	[Opal] Hai Zhao, Xuewu Chui, and Lunxian Xun (2008): Gold Science and Technology 16(1), 48-51
Yanji City ⓘ Wufeng-Wuxingshan Au-(Ag) deposit	[Opal] Renyi Chen and Zhongyao Rui (1993): Mineral Deposits 12(1)
Liaoning Fushun Wanghua District ⓘ Fushun Mine	[Amber] http://www.smartminerals.com/cina2004/art_China_localities.htm
Shandong Linyi Pingyi County Tongshi complex ⓘ Guilaizhuang Au Mine	[Opal] Changfu Chen, Yanbing Li, and Mingxia Jiang (1999): Geological Science and Technology Information 18(1), 60-66
Shanxi Shuozhou Pinglu District ⓘ Qiangfengling Mine	[Opal] Yongtao Zhang and Guiqin Tang (1986): Mineral Deposits 5(1), 63-72
Sichuan Ngawa Autonomous Prefecture (Aba Autonomous Prefecture) Zoigê Co. (Ruo'ergai Co.) ⓘ Dengmo Au deposit	[Opal] Su Sun (1993): Gold Science and Technology 1(2), 4-10
ⓘ Pingding Au-As-Hg deposit (Dingping Au-As-Hg deposit; Xionghuangpo Au-As-Hg deposit)	[Opal] http://www.cicresources.com/PDF_REPORTS/Pingding_F1ReportFinal.pdf
Tibet Lhasa Damxung Co. (Dangxiong Co.) ⓘ Yangbajing sulphur deposit	[Opal] Xiangang Meng, Zhaogang Shao, Chaobin Yang, Weizhi Lei, Jin Wang, Xiangyang Feng, Dagang Zhu, Jia Yu, Jianjun Du, and Jian'en Han (2004): Geological Bulletin of China 23(4), 381-389
Nagchu Prefecture (Naqu Prefecture) Amdo Co. (Anduo Co.) ⓘ Meiduo Sb deposit	[Opal] Shenghao Yan, Jinjie Yu, Yixin Zhao, Zhizhong Xu, Anjian Wang, and Dengkui Su (2003): Mineral Deposits 22(2), 149-157; Jianjun Bu and Qifa Duan (2006): Geological Bulletin of China 25(1/2), 273-276
Xigazê Prefecture (Rikaze Prefecture; Shigatse Prefecture) Ngamring Co. (Angren Co.) ⓘ Targejia Cs deposit (Dagejia Cs deposit; Tagejia Cs deposit)	[Opal] Yuanyi Zhao, Fengjun Nie, Zengqian Hou, Zhenqing Li, Xitao Zhao, and Zhibang Ma (2006): Mineral Deposits [Kuangchuang Dizhi] 25(3), 281-291
Xaitongmoin Co. (Xietongmen Co.) ⓘ Xiongcun Cu-(Au) deposit	[Opal] Xinghai Lang, Juxing Tang, Zhijun Li, Yong Huang, Yuan Chen, and Li Zhang (2011): Mineral Deposits 30(2), 327-338
Xinjiang Kezilesu Autonomous Prefecture (Kizilsu Autonomous Prefecture; Qizilsu Autonomous Prefecture) Aketao Co. (Akto Co.; Aqto Co.) ⓘ Ortokarnash deposit	[Opal] Zhang, Bang-Lu, Zhi-Cheng Lv, Zhi-Guo Dong, Xin Zhang, Xiao-Fei Yu, Yong-Sheng Li, Shi-Min Zhen, and Chang-Le Wang. (2022) "Source Characteristics of the Carboniferous Ortokarnash Manganese Deposit in the Western Kunlun Mountains" Minerals 12, no. 7: 786. https://doi.org/10.3390/min12070786
Turpan Shanshan Co. ⓘ Shiyingtan Mine	[Opal] Lianchang Zhang, Wenjiao Xiao, Kezhang Qin, Jinsheng Ji, and Xingke Yang (2004): International Journal of Earth Sciences 93, 224-240.
Wulumuqi Prefecture (Ürümqi Prefecture; Ürümchi Prefecture) Wulumuqi Co. (Ürümqi Co.; Ürümchi Co.) Chaiwobao Cu ore field ⓘ Xingshugou Cu deposit	[Opal] Jincao Wang, Jianye Wang, Zhengrun Wang, and Ensheng Peng (2000): Geology and Prospecting 36(5), 24-26
Yili Hasake Autonomous Prefecture (Ili Kazakh Autonomous Prefecture) Aletai Prefecture (Altay Prefecture) Jimunay Co. (Jeminay Co.; Jeminey Co.) Eastern Sawur Caldera Complex ⓘ Kuoerzhenkuola Mine (Kurzhenkuola Mine)	[Opal] Fuquan Yang, Jingwen Mao, Bierlein, F.P., Pirajno, F., Caisheng Zhao, Huishou Ye, and Feng Liu (2009): Ore Geology Reviews 35, 217-234.
Xinyuan Co. (Künes Co.) Tu'ergen ⓘ Qiaolekesayi Cu occurrence (Qiaolekesa Cu occurrence)	[Opal-A var: Opal-AN] Wuhan Huaze Science & Technology Development Co. Ltd., 2007
Yunnan Baoshan Tengchong County ⓘ Longchuanjiang basin	[Opal] Dahlkamp, F.J., Ed. (2009): Uranium Deposits of the World. Springer (Berlin, Heidelberg), pp. 31-156
ⓘ Chengzishan Mine (Tengchong Mine; U deposit No. 381)	[Opal] Dahlkamp, F.J., Ed. (2009): Uranium Deposits of the World. Springer (Berlin, Heidelberg), pp. 31-156
ⓘ Rehai geothermal field	[Opal] Meixiang, Z., & Wei, T. (1987). Surface hydrothermal minerals and their distribution in the Tengchong geothermal area, China. Geothermics, 16(2), 181-195.
ⓘ Lianghe Au deposit	[Opal] Pin'an Wang (2001): Bulletin of the Geological Survey of Japan 52(8).
Tengchong Sn belt ⓘ Tieyaoshan W-Sn deposit	[Opal] Shilu Zhang (1986): Mineral Deposits 5(3), 19-26
Chuxiong Chuxiong City ⓘ Xiaoshuijing Mine	[Opal] Yunman Zhou, Jingwen Mao, and Changqing Zhang (2009): Geology and Exploration 45(5), 588-594; Yunman Zhou, Changqing Zhang, Shuqiong Wang, and Xiuping Qin (2012): Mineral Deposits 31(1), 52-64
Dehong Lianghe County Tengchong Sn belt ⓘ Lailishan Sn deposit	[Opal] Shilu Zhang (1986): Mineral Deposits 5(3), 19-26
Mangshi (Mang City) ⓘ Shangmanggang Au deposit	[Opal] http://www.spartonres.ca/download/Luxi-Sedar(02-02).pdf
Pu'er Mojiang County ⓘ Jinchang Mine (Mojiang Mine; Yuanjiang gold mine)	[Opal] Guangjun Yu and Ruyong Xie (1986): Geology and Prospecting 22(2), 11-18; Yuan Li (1998): Geology and Prospecting 34(5), 28-32
Qujing Huize County Huize Zn-Pb-(Ag) ore field ⓘ Kuangshanchang Zn-Pb deposit	[Opal] Senning Tang (1984): Geology and Prospecting 24(12), 1-9
Zhejiang Jinhua Wuyi County ⓘ Wuyi fluorite ore field	[Opal] Panov, B.S., and Hongquan Yan (1989): Geology and Prospecting 25(10), 1-5

Colombia
Boyacá Department Chivor ⓘ Chivor Mine	[Opal-A var: Opal-AN] Emeralds of the World English extraLapis Vol. 2 2002 pp36-45
ⓘ Santander Department	[Amber] Dmitry Vorobjov's collection
ⓘ Valle del Cauca Department	[Opal] Daniel S Yunis

Costa Rica
Guanacaste Province ⓘ Loma Camastro	[Opal] www.mineralmundi.com
ⓘ Los Angeles	[Opal] www.mineralmundi.com
San José Province ⓘ Guaitil de Acosta	[Opal] Zeledón, L.A. (2004) Zeolitas del Valle Central de Costa Rica y sus alrededores. Revista Geológica de América Central, 31: 67-80 [in Spanish].

Cuba	[Opal] Mineral Collector 10:118 (1903)


Czech Republic
Central Bohemian Region Benešov District ⓘ Bernartice	[Opal] Kratochvíl, F.: Příspěvek k petrografii českého krystalinika. In Sborník geologického ústavu Československé republiky, 1947, sv. 14, s. 449-536.
ⓘ Roudný deposit	[Opal] Zemek, V.: Zlatodůl Roudný u Vlašimi. Pod Blaníkem, 5. samostatná příloha, 2001: Podblanické ekocentrum Českého svazu ochránců přírody a Muzeum okresu Benešov, 108 s.
ⓘ Kladno District	[Opal] Zacek, V., Oplustil, S., Mayova, A. & Meyer, F. R. (1995): Die Mineralien von Kladno in Mittelböhmen, Tschechische Republik. Mineralien-Welt 6 (1), 13-30 (in German).
ⓘ Vinařice	[Opal] Pauliš, P.: Nejzajímavější mineralogická naleziště Čech. Kutná Hora: Kuttna, 2000, s. 84-85.
Kutná Hora District Vlastějovice (Hammerstadt) Moldanubian Zone pegmatites Magdalena deposit ⓘ Hydrothermally altered amphibole-bearing pegmatite	[Opal] Novak, M., Kadlec, T., & Gadas, P. (2013). Geological position, mineral assemblages and contamination of granitic pegmatites in the Moldanubian Zone, Czech Republic; examples from the Vlastejovice region. Journal of Geosciences, 58(1), 21-47.
Hradec Králové Region Jičín District Lázně Bělohrad Hřídelec ⓘ Hřídelec quarry	[Opal] http://www.mineralos.cz/lokality/hridele/uhride.htm
Karlovy Vary Region Karlovy Vary District ⓘ Jáchymov	[Opal] Lapis 2002(7/8), 63-65
Potůčky ⓘ Marie Terezie vein	[Opal] Bufka, A., Velebil, D.: Manganová mineralizace žíly Marie Terezie u Horní Blatné v Krušných horách. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 2003, roč. 11, s. 100-114.
Valeč ⓘ Valeč Hyalite occurrences	[Opal-A var: Opal-AN] No reference listed
Sokolov District ⓘ Oloví	[Opal] Pauliš P. Nejzajímavější mineralogická naleziště Čech II. Kuttna. Kutná Hora 2003. ISBN 80-86406-27-X.
Rovná Čistá ⓘ Jeroným Mine	[Opal] Janečka, J., Just, J., Kušnír, I.: Zpráva o výzkumu a výpočet zásob Sn-rud na ložisku Jeroným v Čisté ve Slavkovském lese (stav ke dni 1.7.1966). Loket: MS, Ústřední ústav geologický Praha, 1966. 86 s.
Liberec Region ⓘ North Bohemian Uranium District	[Opal] Scharm, B.: Přehled minerálů nalezených v oblasti uranových koncentrací v severočeské křídě. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 1995, roč. 3, s. 169-172.
Semily District Harrachov ⓘ Fluorite deposit	[Opal] Fengl, M.: Mineralogie těžených fluoritových ložisek (1.-5.). Minerál, 1998-1999, roč. 6-7, č. 2, 4, 6, 1, 3.
Radostná pod Kozákovem ⓘ Votrubec quarry	[Opal] Pauliš, P.: Nejzajímavější mineralogická naleziště Čech. Kutná Hora: Kuttna, 2000, s. 57-58.
Olomouc Region Jeseník District Skorošice ⓘ Skorošice quarry	[Opal] Kruťa, T.: Nerostný výzkum ve Slezsku v letech 1956-1957. Přírodovědecký sborník Ostravského kraje, 1957, 18, 543-571.
Pardubice Region Pardubice District ⓘ Chvaletice	[Opal] Prachař, I.: Současný stav výskytu nerostů ve Chvaleticích. Acta musei Reginaehradecensis, série A: vědy přírodní, 1981, roč. XVI., s. 99-102.
ⓘ Litošice	[Opal] Zak, L. (1956): Alabandite from Litosice in the Iron Mountains (Bohemia). Rozpravy Ceskoslov. akad. ved, Rada mat. a prirod. ved 66 (No. 13), 49-78. Hybler, J., Dolníček, Z., Sejkora, J. (2021): Cronstedtite from Litošice, Czech Republic. Journal of Geosciences, 66, 227-242.
Ráby ⓘ Kunětická hill	[Opal] Pauliš P. Mineralogické lokality okolí Kutné Hory. Kuttna, Kutná Hora 1999. ISBN 80-9027 19-0-1.
Plzeň Region Klatovy District Hejná ⓘ Radvanka quarry	[Opal] Hofmanovi P. a R.: Mineralizace vápencového lomu na vrcholu Radvanka u Hejné. Minerál, 2010, 18, 3, 201-211.
Rokycany District Těškov ⓘ Těškov quarry	[Opal] Janouš, F.: Minerály z Kněží hory u Těškova (okres Rokycany), Minerál, 1995, roč. 3, č. 6, s. 367-369.
Tachov District Černošín ⓘ Vlčí hora	[Opal] Navrátil, Z., Šrein, V.: Krystalovaný olivín v tufech Vlčí hory u Černošína. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 1997, roč. 4-5, s. 177-178.
ⓘ Stříbro	[Opal] Pauliš, P.: Nejzajímavější mineralogická naleziště Čech II. Kutná Hora: Kuttna, 2003, s. 111-114.
South Bohemian Region České Budějovice District ⓘ Vrábče	[Opal] Boris Pralovszky find & collection
Český Krumlov District ⓘ Kremze	[Opal] Duda, Rejl, Slivka: "Mineralien", 1991; Čech, V., Koutek, J.: Geologické a genetické poměry ložisek železné a niklové rudy u Křemže v jižních Čechách. Sborník St. geol. úst. ČSR, 1946, sv. 13,
Bohouškovice ⓘ Bohouškovice opal occurrences	[Opal] No reference listed
Písek District Čížová ⓘ Phosphate occurrence	[Opal-A var: Opal-AN] Cícha J., Sejkora J.: Vanadový wavellit, variscit a další fosfáty z grafitických kvarcitů v Čížové u Písku. Minerál, 2011, 19, 1, 23-32.
Strakonice District Krty-Hradec ⓘ Krty quarries	[Opal] Litochleb, J. et al.: Korund ze skapolitem bohaté vápenatosilikátové horniny v moldanubických mramorech u Krtů na Strakonicku. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 1997, roč. 4-5, s. 169-172.
Tábor District Dolní Hořice ⓘ Pacova Hill quarry	[Opal] http://www.mineralos.cz/lokality/chynov/chynov.htm
ⓘ Ratibořské Hory	[Opal] Vrtiška, L., Malíková, R., Dolníček, Z., & Sejkora, J. (2019). Pyromorphite, kintoreite and cerussite from the historical Ag-Pb-Zn ore deposit Ratibořské Hory (Czech Republic). Bulletin Mineralogie Petrologie, 27(2), 394-410.
South Moravian Region Blansko District Letovice ⓘ Slatinka	[Opal] Ulrych, J.: Stichtit z hadcového tělesa od Slatinky u Letovic. Časopis pro mineralogii a geologii, 1966, roč. 11, č. 3, s. 311-315.
Rudice ⓘ Seč quarry	[Opal] Dana RICHTEROVÁ, Antonín PŘICHYSTAL and Zdeněk LOSOS, "Moravian Jurassic Geodes and their Geological Significance," GeoLines 13, 2001, p. 106. (http://geolines.gli.cas.cz/fileadmin/volumes/volume13/G13-106.pdf)
Brno-City District ⓘ Černovice	[Opal] Mrázek, I.: Nová nelaziště achátu a opálu u Brna-Černovic. Časopis pro mineralogii a geologii, 1976, roč. 21, č. 1, s. 96.
Brno-Country District ⓘ Dolní Loučky ?	[Opal] Uwe Kolitsch (visual ID)
Ivančice Hrubšice ⓘ U Pustého Mlýna Quarry	[Opal] Jirásek, J.: Nový nález huntitu u Hrubšic na západní Moravě a otázka jeho vzniku. Acta Musei Moraviae, Sci. geol., 2007, roč. 92, s. 103-109.
ⓘ Nedvědice	[Opal] Houzar, S., Novák, M., Doležalová, H., Hrazdil, V., Pfeiferová, A.: Přehled mineralogie, petrografie a geologie nedvědických mramorů, svratecké krystalinikum. Acta Musei Moraviae, Sci. geol., 2006, roč. 91, s. 3-77.
Nová Ves ⓘ Serpentinite occurrence	[Opal] Koníčková Š., Losos Z., Hrazdil V., Houzar S., Všianský D. (2016): Mineralogie „očkových“ opálů z Nové Vsi u Oslavan (moldanubikum, Český masív). Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze 24, 1: 144-158.
Ústí nad Labem Region Chomutov District Březno ⓘ Libous quarry	[Opal] Chukanov, N. V., Pekov, I. V., Sejkora, J., Belakovskiy, D. I., & Britvin, S. N. (2019). Ferrierite-NH4,(NH4, Mg0. 5) 5 (Al5Si31O72)· 22H2O, A New Zeolite from Northern Bohemia, Czech Republic. The Canadian Mineralogist, 57(1), 81-90.
Kadaň Tušimice ⓘ Nástup Quarry	[Amber] Bouška, V., Dvořák, Z.: Nerosty severočeské hěndouhelné pánve. Praha: Severočeské doly, a.s., 160 s.
Klášterec nad Ohří ⓘ Roadcut on highway no. 13	[Opal] Wiesner, T.: Nová lokalita minerálů zeolitové skupiny u Klášterce nad Ohří. Časopis pro mineralogii a geologii, 1984, roč. 29, č. 4, s. 432.
Málkov Ahníkov ⓘ Ahníkov pyroxenite outcrop	[Opal] Řehoř, M., Dvořák, Z.: Nové poznatky o mineralogii lokality Ahníkov. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 1997, roč. 4-5, s. 183-185.
Děčín District Děčín Folknáře ⓘ Pustý Vrch	[Opal] Pauliš P., Hrůzek L., Janeček O., Dvořák Z., Toman J., Svejkovský J., Radoň M. (2015) Nejzajímavější mineralogická naleziště Čech – zeolity a doprovodná mineralizace. 1.Dil. Kutná Hora. (page 66)
Jílové ⓘ Fluorite deposit	[Opal] Fengl, M.: Mineralogie těžených fluoritových ložisek (4.). Minerál, 1999, roč. 7, č. 1, s. 38-53.
Litoměřice District Úštěk ⓘ Pohorsko-Pohorský Hill	[Opal] P.Zeman,P.Pauliš,P.Pour,R.Malíková (2017) Zeolites of Pohorský Hill and district. mag.Minerál 2017/2
Louny District Libčeves Hořenec (Horzenz; Horschenz) ⓘ Číčov hill (Spitzberg)	[Opal] Filippi, M., Filippi, R.: Hořenec u Bíliny – světová lokalita krystalů aragonitu. Minerál, 2004, roč. 12, č. 3, s. 188-195.
Most District Braňany ⓘ Bentonite deposit Braňany II - Černý vrch	[Opal] Svejkovský J., Dvořák Z.., Řehoř M., Muzikant P.: Zajímavá mineralizace bentonitového lomu v Braňanech u Mostu. Minerál, 2013, 21, 6, 541-547.
Korozluky (Kolosoruk; Kolloseruk) ⓘ Korozluky magmatic rock occurrence (Kolosoruk magmatic rock occurrence; Kolloseruk magmatic rock occurrence)	[Opal] Filippi, M.: Korozluky – pozoruhodná mineralogická lokalita Českého středohoří. Bulletin mineralogicko-petrografického oddělení Národního muzea v Praze, 2002, roč. 10, s. 320-322.
ⓘ Lužice	[Opal] Roman Gramblička collection
Most ⓘ Komořany (Kommern)	[Amber] Bouška, V., Dvořák, Z.: Nerosty severočeské hěndouhelné pánve. Praha: Severočeské doly, a.s., 160 s.
ⓘ Vršany (Würschen)	[Amber] Petr Fuchs
Teplice District Bílina ⓘ Bílina coal mine	[Amber] Petr Fuchs specimen
Bžany ⓘ Hradiště	[Opal] Velebil, D.: Bílina – Hradiště, klasické naleziště „cimolitu“ a „anauxitu“. Minerál, 2005, roč. 13, č. 6, s. 413-419.
Krupka Vrchoslav ⓘ Vrchoslav fluorite deposit	[Opal] Analysed by geology lab Green Gas DPB
Zabrušany ⓘ Želénky	[Opal] Bouška, V., Dvořák, Z.: Nerosty severočeské hěndouhelné pánve. Praha: Severočeské doly, a.s., 160 s.
Ústí nad Labem District Chuderov Radešín ⓘ Radešín hill	[Opal-A var: Opal-AN] www.geocities.com/Smula.geo
ⓘ Žežice	[Opal-A var: Opal-AN]
Řehlovice Radejčín (Radzein) ⓘ Starý hill (Alter Berg)	[Opal-A var: Opal-AN] Radoň M. Významné mineralogické lokality Českého středohoří. Minerál 2009, XVII(2):106-126.
Ústí nad Labem ⓘ Brná	[Opal] P.Pauliš
ⓘ Mariánská Skála (Mariánská hora; Marienberg)	[Opal] Ulrych, J. et al. (2000): Tertiary phonolite laccolith of Mariánská hora hill, N. Bohemia: geological, petrological and mineralogical characteristics. Acta Montana IRSM AS CR, series A No. 15 (116), p. 5-44.
ⓘ Mojzir	[Opal-A var: Opal-AN]
Vysočina Region Třebíč District Dukovany ⓘ Dukovany opal occurrence	[Opal] Slavíček, P, Beneš, M.: Zajímavý výskyt opálů v Dukovanech na Třebíčsku. Časopis pro mineralogii a geologii, 1985, roč. 30, č. 3, s. 333.
ⓘ Jemnice	[Opal] Houzar, S., Pošmourný, K.: Ag-Pb-Zn rudní mineralizace u Jemnice na jihozápadní Moravě. Acta Musei Moraviae, Scientiae naturales, 1991, roč. 76, s. 95 - 103.
Mohelno ⓘ Bliemsried quarry	[Opal] Němec, F., 1937: Mineralogie, petrografie a geologie okolí Mohelna. Monografie hadce (monografie hadce). – In: Archiv Svazu pro ochranu přírody a domoviny v zemi Moravskslezské, Brno, 49-112.
Třebíč Řípov ⓘ Residual rocks outrop	[Opal] Trnka M, Švorcová L (2006) Opály v západním okolí Třebíče. Minerál 14(6): 458-463
Žďár nad Sázavou District ⓘ Bobrůvka	[Opal] Paulis P. (2001): Nejzajimavejsi mineralogicka naleziste Moravy a Slezska. Kuttna, Kutna Hora.
Bory ⓘ Dolní Bory	[Opal] Staněk, J.: Parageneze minerálů pegmatitových žil z Hatí u Dolních Borů na západní Moravě. Acta Mus. Moraviae, Sci. nat., vol. 76, pages 19-49.
ⓘ Pegmatite vein Oldřich	[Opal] Staněk, J.: Asociace minerálů významnějších pegmatitových žil v Hatích u Dolních Borů na západní Moravě. Acta Musei Moraviae, Scientiae naturales, 1997, roč. 82, 3-19.
Býšovec ⓘ Smrček	[Opal] Petr Pauliš (2001): Nejzajímavější mineralogická naleziště Moravy a Slezska. Kuttna, Kutná Hora.
ⓘ Dobrá Voda	[Opal] Novák, M., Staněk, J.: Lepidolitový pegmatit od Dobré Vody u Velkého Meziříčí, západní Morava. Acta Musei Moraviae, Scientiae geologicae, 1999, roč. 84, s. 3 - 44.
Rožná ⓘ Rožná (Opál)	[Opal] Petr Pauliš: Nejzajímavější mineralogická naleziště Moravy a Slezska II.(2005)
ⓘ Rožná pegmatite (Rozna; Roschna)	[Opal] Novák, M., Houzar, S., Pfeiferová, A.: Přehled mineralogie, petrografie a historie klasické lokality lepidolitového pegmatitu v Rožné u Bystřice nad Pernštejnem, západní Morava. Acta Musei Moraviae, Sci. geol., 83:3-48.
Štěpánov nad Svratkou ⓘ Borovec (Borowetz; Borowitz?)	[Opal] Velebil, D., Kráčmar, L.: Ložisko Borovec u Štěpánova (štěpánovský revír). Minerál, 2002, roč. 10, č. 3, s. 163-181.
ⓘ Věchnov	[Opal] Kopa, D.: Mineralogie a petrografie hadce od Věchnova. Časopis Slezského musea, series A: vědy přírodní, 1960, roč. 9, s. 17-24.
Věžná ⓘ Věžná I pegmatite	[Opal] Canadian Mineralogist, Vol 17, 1979, pp. 583-588.; Cerny, P., Hawthorne, F. C., Laflamme, J. H. G., & Hinthorne, J. (1979). Stibiobetafite, a new member of the pyrochlore group from Vezna, Czechoslovakia. Canadian Mineralogist, 17, 583-588.
ⓘ Věžná serpentinite quarry	[Opal] http://pruvodce.geol.morava.sci.muni.cz/Vezna_hadec/Vezna_hadec_text.htm; Petr Pauliš (2001): Nejzajímavější mineralogická naleziště Moravy a Slezska. Kuttna, Kutná Hora.
Zlín Region Uherské Hradiště District Komňa ⓘ Bučník Hill Quarry	[Opal] Pauliš, P: Nejzajímavější mineralogická naleziště Moravy a Slezska. Kutná Hora: Kuttna, 2001, s. 42-44.

Czech Republic/Germany/Poland
ⓘ Silesia	[Opal] Bauer & Bouska, 1983. Precious & Semi-precious Stones

Denmark	[Amber] http://www.ravsiden.dk/ ; Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.

Capital Region ⓘ Bornholm Island	[Amber] - Langenheim J. H. (1969): Amber. A botanical inquiry. Science, 163, 1157-1169. - Larsson S.G. (1978): Baltic Amber - a Palaeobiological Study. Entomograph Volume 1. Scandinavian Science Press Ltd., Klampenborg - Denmark, 192 pp.
Central Denmark Region Skive ⓘ Fur Island	[Opal] Bøggild (1943); Pedersen, S. A. S. (2008). Palaeogene diatomite deposits in Denmark: geological investigations and applied aspects. Geological Survey of Denmark and Greenland Bulletin, 15, 21-24.
North Jutland Region Morsø Mors Island ⓘ Hanklit	[Opal] Torben Kjeldgård photo & specimen
Hesselbjerg ⓘ Skarrehage Moler quarry	[Opal] Bøggild (1943); Bøggild (1943)

Dominican Republic
Hato Mayor Province ⓘ Sabana de la Mar (Sabana)	[Amber] http://www.gplatt.demon.co.uk/dominica.htm
Sánchez Ramírez Province Cotuí ⓘ Lignite deposits	[Amber] http://www.gplatt.demon.co.uk/dominica.htm
Santiago Province ⓘ Cordillera Septentrional	[Amber] http://www.gplatt.demon.co.uk/dominica.htm
ⓘ Santiago de Los Caballeros	[Amber] Raúl Joreg Tauber Larry
ⓘ La Toca amber mines	[Amber] Raúl Jorge Tauber Larry

DR Congo
Haut-Katanga Kambove Shinkolobwe ⓘ Shinkolobwe Mine	[Opal] MinRec 20:287-288
Kasaï ⓘ Kasai river alluvials	[Opal] Edwards, M.G. (1917) The American Mineralogist, 2, #7, 88-89.
Lualaba Mutshatsha Kolwezi mining district ⓘ Tilwezembe mine	[Opal-A var: Opal-AN] Uwe Haubenreisser collection

Ecuador	[Opal] Rocks&Min 51:11

Chimborazo Province Alausi Canton ⓘ Tixan	[Opal] http://www.municipiodealausi.gob.ec/UserFiles/File/TIXAN.pdf
Guayas Province Guayaquil Canton Guayaquil ⓘ Faculty of Natural Science construction site	[Opal] Ordoñez, Marta (2006): MICROPALEONTOLOGÍA ECUATORIANA. CIGG: PETROPRODUCCION. p : 85,86.
Zamora-Chinchipe Province ⓘ Fruta del Norte Au-Ag deposit	[Opal] Hennessey, B.T., Puritch, E.J., Gowans, R.M., Leary, S.F., (2008) A mineral resource estimate for the Fruta Del Norte deposit, Cordillera del Condor Project, Zamora-Chinchipe Province, Ecuador; an NI 43-101 Technical Report prepared for Kinross Gold Corporation by Micon International Limited, 232p.

Egypt
Giza Governorate ⓘ Bahariya Oasis (Baharia Oasis)	[Opal] S. Tosson et al. , Bull. Soc. Fr. Minéral. Cristallogr. , 1974, 97, pp. 27-39.

Ethiopia
Afar Region ⓘ South Gondar Opal Occurrences	[Opal] Ethiopian Gem Association Ethiopian Gem Association http://tracktech.net/ega/index.php
Amhara Region North Shewa Zone ⓘ Mezezo Opal Occurrence	[Opal] GIA 2019
ⓘ Yita ridge	[Opal] Gem Information, 23 May 2007 (Japan Germany Gemmological Laboratory), 20-24.
Mida (Midda) ⓘ Amber occurrence	[Amber] www.ambergallery.it
ⓘ North Wollo Zone	[Opal] Chauviré, B., Rondeau, B., Mazzero, F., Ayalew, D. (2017) The Precious Opal Deposit At Wegel Tena, Ethiopia: Formation VIA Successive Pedogenesis Events. The Canadian Mineralogist, 55:4, 701.
ⓘ Delanta Woreda	[Opal] Boris Chauviré, Benjamin Rondeau, Anne Alexandre, Sarah Chamard-Bois, Carole La, Francesco Mazzero. (2019) Pedogenic origin of precious opals from Wegel Tena (Ethiopia): Evidence from trace elements and oxygen isotopes. Applied Geochemistry Vol. 101, pp 127-139. ISSN 0883-2927
ⓘ Tsehay Mewcha	[Opal] Schäfer, K. (2012) Feuer im Wasser: Die Vorkommen von neuartigem Edelopal in Äthiopien. Lapis 37:2, 13-16.
ⓘ Wegeltena	[Opal] Rondeau, B., Fritsch, E., Mazzero, F., Gauthier, J.-P., Cenki-Tok, B., Bekele, E., Gaillou, E. (2010) Play-of-Color Opal from Wegeltena, Wollo Province, Ethiopia. Gems & Gemology, Vol. 46:2, 90–105.
Wadla Woreda ⓘ Gashena	[Opal] Lore Kiefert, Pierre Hardy, Tewodros Sintayehu, Begosew Abate, and Girma Woldetinsae (2014) New Deposit of Black Opal from Ethiopia. Gems & Gemology Winter 2014, Vol. 50, No. 4
ⓘ South Wollo Zone	[Opal] Rondeau B., Mazzero F., Bekele E., Gauthier J.-P., Fritsch E. (2009) Gem News International: New play-of-color opal from Welo, Ethiopia. Gems & Gemology, Vol. 45:1, 59–60.
Tenta Woreda ⓘ Ajebar mine	[Opal] Google Earth/José Zendrera
Oromia Region Hawasa ⓘ Shalo hot spring	[Opal] Žáček V, Rapprich V, Šíma J, Škoda R, Laufek F, Legesa F (2015): Kogarkoite, Na3(SO4)F, from the Shalo hot spring, Main Ethiopian Rift: implications for F-enrichment of thermal groundwater related to alkaline silicic volcanic rocks. Journal of Geosciences, 60, 171-179.
ⓘ Lake Shala (Lake Shalla)	[Opal] Alfredo Petrov field observations, 1972.
Somali Region Jijiga ⓘ Marda Pass ?	[Opal] Jelenc, Danilo A. (1966) Mineral Occurrences of Ethiopia, p 563.
Southern Nations Nationalities and Peoples' Region ⓘ Arbegona District	[Opal-A var: Opal-AN] (Rock Currier collection)

Europe
ⓘ Albera Massif	[Opal] Berbain,C., Riley, T., Favreau, G., (2012): Phosphates des pegmatites du massif des Albères (Pyrénées-Orientales). Le Cahier des Micromonteurs. 117, 121-172
Ore Mountains ⓘ Zinnwald-Cínovec mining region	[Opal] Petr Fuchs

Faroe Islands	[Opal] Claus Hedegaard collection (nos. 613, 7010, 7242 a.o.)

Norðoyar Region Borðoy Ánirnar ⓘ Strond Quarry	[Opal] Zeolite collection of Volker Betz; SMLS Journal 234 Nov/Dec 2011
Streymoy Region Streymoy ⓘ Hoyvik	[Opal] Caucia, F., Marinoni, L., Leone, A. (2013): Physical, geochemical and gemological properties of opals from Faroe Islands. Neues Jahrbuch für Mineralogie - Abhandlungen.191, 33-43
ⓘ Tórshavn	[Opal] Caucia, F. Marinoni, L. Leone, A. (2013) Physical, geochemical and gemological properties of opals from Faroe Islands. N. Jb. Miner. Abh. (J. Min. Geochem.) 191/1 (2013), 33–43

Fiji
Vanua Levu Nukundamu ⓘ Undu mine ("Udu mine")	[Opal]

Finland
Kanta-Häme Forssa ⓘ Kiimassuo pegmatite	[Opal] Ilkka Mikkola collection
Kymenlaakso Kotka ⓘ Topaz quarry	[Opal] Lahti Seppo I. 2011. Kotkan topaasilouhoksesta ja sen mineraaleista. Kivi-lehti 4.
Ostrobothnia Korsnäs ⓘ Korsnäs Lead Mine	[Opal] The world of opals By Allan W. Eckert
South Karelia Luumäki Kännätsalo ⓘ Karelia Beryl Mine pegmatite	[Opal] P. Koski sample
South Ostrobothnia Alavus ⓘ Töysä	[Opal] Joel Dyer Collection
Southwest Finland Salo Suomusjärvi ⓘ Salittu	[Opal] Niskanen, Maria (2014). Salitun felsisten juonten mineraalikoostumus ja evoluutio. Pro Gradu-tutkielma (2014). Geotieteiden ja Maantieteen Laitos Helsingin Yliopisto.gedrite

France
Auvergne-Rhône-Alpes Allier Montluçon ⓘ Chamblet	[Opal] M Arliguie collection
Moulins Saint-Hilaire ⓘ Montalimbert mine	[Opal] Périchaud, J.-J. (1985) Où trouver les minéraux d'Auvergne, Vol. 1 Puy de Dôme-Allier, L'instant Durable, Clermont-Ferrand.
Ardèche Privas ⓘ Saint-Bauzile	[Opal] Yves Masson specimens
Saint-Priest ⓘ Col de l'Escrinet	[Opal] Bull. Soc. Franç. Minéralo. Cristallo. , 1974, 97, pp. 450-464.
Cantal Mauriac Menet ⓘ Puy de Menoyre	[Opal] Vessely Yannick collection
Saint-Flour Laveissière Le Lioran ⓘ Plomb du Cantal	[Opal] Yves Masson specimen
Val-d'Arcomie ⓘ Clavières d'Outre	[Opal] http://www.brgm.fr/volcan/ressourcesmin.htm
ⓘ Faverolles quarry	[Opal-A var: Opal-AN] Robin Fialip
Haute-Loire Brioude Chastel ⓘ Moulergues	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
Jax ⓘ La Ribeyrette & La Fauvette valleys (La Fioure; La Fiouve)	[Opal]
Mazeyrat-d'Allier ⓘ Rassac	[Opal-A var: Opal-AN] Pierre Le Roch collection
Saint-Beauzire ⓘ La Violette farm	[Opal] P.G. Pélisson : "Etude Minéralogique et Métallogénique du District Filonien Polytype de Paulhaguet (Haute-Loire, Massif Central Français)", Doctorate Thesis, Orléans, France, 1989
Le Puy-en-Velay Ceyssac ⓘ Mont Croustet	[Opal-A var: Opal-AN] Collected by Stéphane Jamon
Landos ⓘ La Sauvetat ?	[Opal-A var: Opal-AN] Aufschluss 1974(3), 193-197
ⓘ Saint-Pierre-Eynac	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
Yssingeaux Araules ⓘ Courcoules	[Opal] Périchaud, J.-J. (1986): Où trouver les minéraux d`Auvergne. II (Cantal-Haute-Loire). Éditions L`Instant Durable, 1986, 112p. (p.23)
Loire Montbrison Châtelneuf ⓘ Mont Semiol	[Opal-A var: Opal-AN] Anthony Geneyton Collection
Roanne Ambierle ⓘ Hauteville	[Opal] BRGM (1981) - Fiche BSS 06478X4001/GT
Saint-Étienne Saint-Priest-en-Jarez ⓘ Le Crêt	[Opal] G. Demarcq, 1973, "Guides Géologiques Régionaux : Lyonnais, Vallée du Rhône" , p. 88, Masson.
Puy-de-Dôme Ambert ⓘ Cunlhat	[Opal]
Clermont-Ferrand Clermont-Ferrand ⓘ Puy de Crouel	[Opal] Remi Bornet Collection
La Roche-Blanche ⓘ Gergovie	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.; Périchaud, J.-J. (1985) Les Minéraux d'Auvergne, Vol. 1.
Lempdes ⓘ Gandaillat quarry	[Opal] Remi Bornet Collection
ⓘ Puy de la Bourrière	[Opal] Remi Bornet Collection
Mur-sur-Allier ⓘ Les Rois Mine	[Opal] Aimé Rudel : "Curiosités Géologiques d'Auvergne et du Velay", Editions Volcans, 1970
ⓘ Puy du Mur Quarry	[Opal] Remi Bornet Collection
ⓘ Pont-du-Château	[Opal] Remi Bornet Collection
ⓘ Champ des Poix mine	[Opal] Remi Bornet Collection
Romagnat Saulzet-le-Chaud ⓘ Côte des Pompes	[Opal] "Les minéraux, leurs gisements, leurs associations", P. Bariand, F. Cesbron et J. Geffroy (1977), Editions Minéraux et Fossiles, BRGM
Issoire Besse-et-Saint-Anastaise ⓘ Pavin lake	[Opal] http://gsa.confex.com/gsa/inqu/finalprogram/abstract_54492.htm / The XVI INQUA Congress, Reno, Nevada, USA
Gignat ⓘ La Chaux de Bergonne	[Opal] G. Artioli et al. , Am. Min. , V84, 1999, pp. 1445-1450.
Perrier ⓘ Roca-Neyra ?	[Opal] my collection
Saint-Babel ⓘ Prudeux	[Opal-A var: Opal-AN] Barrier, D., Devolle, J.-C., Médard, P, Naud, E. Naud & Pourtier, G. (2009): Si l'amesite m'était Comté... ou pas d'haüyne à Prudeux, Le Cahier des Micromonteurs, 103, 3-8.
Saint-Nectaire ⓘ Mineral spring	[Opal] Alain TUEL collection
Riom ⓘ Lussat	[Opal] Mallard, E., 1890, Bull. Soc. Min., v13, p. 63
Saint-Jacques-d'Ambur ⓘ La Barre Mine (La Martinèche Mine)	[Opal]
Saint-Ours-les-Roches ⓘ Puy de Tunisset	[Opal] Mboungou-Kongo J.B. (2002), L'hématite spéculaire du puy de Tunisset, Chaîne des Puys (Puy de Dôme), Le Régne Minéral, n°46, pp: 51-55
Thiers Lachaux ⓘ Bigay Mine	[Opal] J.-J. Périchaud: "Où trouver les minéraux d'Auvergne", Vol. 1, Editions l'Instant Durable (Clermont-Ferrand), 1985, p. 92
ⓘ Etang de Reliez	[Opal] J.-J. Périchaud: "Où trouver les minéraux d'Auvergne", Vol. 1, Editions l'Instant Durable (Clermont-Ferrand), 1985, p. 92
ⓘ Gourniaud Mine	[Opal] P.-C. Guiollard (2002), L'uranium du Morvan et du Forez, Ed. P.-C. Guiollard, Fichous(64), 95 pp.
ⓘ Roffin Mine	[Opal] Queneau Patrice Collection
Puy-Guillaume Philibin ⓘ Rez de Sol	[Opal]
Ris ⓘ Bancherelle Mine	[Opal]
ⓘ Gagnol Mine	[Opal] J. Geffroy, J.A. Sarcia, J. Chervet : "Les Minéraux Uranifères Français", 1960, Institut National des Sciences et Techniques Nucléaires / Saclay - PUF.
ⓘ Reliez	[Opal] J. Chervet, G. Branche : "Contribution à l'étude des minéraux secondaires d'uranium français", ENSP Nancy, 1955
Saint-Rémy-sur-Durolle ⓘ Unnamed quartz-pitchblende vein	[Opal] J. Chervet and G. Branche : "Contribution à l'Etude des Minéraux Secondaires d'Uranium Français", ENSG, Nancy, 1955
Rhône Villefranche-sur-Saône Chessy ⓘ Chessy copper mines	[Opal] Coueille, G. (1988). Chessy les Mines. Le Cahier des Micromonteurs, 22(4), 6-46.
Bourgogne-Franche-Comté Saône-et-Loire Mâcon Bonnay Besanceuil ⓘ La Roche	[Opal] OLLIC Pascal Collection
Brittany Côtes-d'Armor Guingamp Trémargat ⓘ Gwernavalou Quarry	[Opal] Germain C., Guillou A. (1988), Le Cahier des Micromonteurs, n°3, 3-7
Saint-Brieuc ⓘ Saint-Lubin	[Opal] Bibinger, G. et Lysiak, J.-L.(2014) - L'opale noire de Saint-Lubin, Plémet, Côtes-D'Armor. Le Règne Minéral, 120, pp. 54-55, editions du Piat.
Ille-et-Vilaine Fougères-Vitré ⓘ Fougères	[Opal] Yann Lukas (1978) Roches et minéraux de Bretagne
ⓘ Fougères Forest	[Opal] John Brunet collection
Le Pertre ⓘ LGV construction site (railroad)	[Opal] BRUNET, J. (2016) - Minéralogie du Massif du Pertre, Ille-et-Vilaine. Le Règne Minéral, 127, 5-18.
Morbihan Pontivy Guern ⓘ Quistiav (Quistiave)	[Opal] R. Pierrot, L. Chauris, C. Laforêt and F. Pillard : "Inventaire Minéralogique de la France N° 9 : Morbihan", BRGM, 1980.
Centre-Val de Loire Cher Vierzon ⓘ Quincy	[Opal] The Quincyte pigments: fossil quinones in an Eocene clay mineral. W.G. Prowse, K.I. Arnot, J.A. Rechka, R.H. Thomson and J.R. Maxwell. Tetrahedron 47, 1991, 1095-1108. K.I.
Indre-et-Loire Loches Paulmy ⓘ Paulmy quarry	[Opal] COCHER, C. (2015) - L'opale de la carrière de Paulmy, Indre-et-Loire. Le Règne Minéral, 126, pp. 51-52
French Polynesia Wallis and Futuna ⓘ Analkele deposit	[Opal] Pelleter, E., Fouquet, Y., Etoubleau, J., Cheron, S., Labanieh, S., Josso, P., ... & Langlade, J. (2017). Ni-Cu-Co-rich hydrothermal manganese mineralization in the Wallis and Futuna back-arc environment (SW Pacific). Ore Geology Reviews, 87, 126-146.
ⓘ Utu Uli deposit	[Opal] Pelleter, E., Fouquet, Y., Etoubleau, J., Cheron, S., Labanieh, S., Josso, P., ... & Langlade, J. (2017). Ni-Cu-Co-rich hydrothermal manganese mineralization in the Wallis and Futuna back-arc environment (SW Pacific). Ore Geology Reviews, 87, 126-146.
Guadeloupe Basse-Terre Vieux-Habitants ⓘ Madeleine-Soufrière volcanic massif	[Opal] Olivier Mével spécimen
Ile-de-France Essonne Palaiseau Bruyères-le-Châtel ⓘ Arpenty quarry	[Amber] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
ⓘ Paris	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
ⓘ Ménilmontant	[Opal]
Val-d'Oise Argenteuil Cormeilles-en-Parisis ⓘ Lambert Quarry	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
Martinique Arrondissement of La Trinité Grand'Rivière ⓘ Montagne Pelée	[Opal] Lacroix, A. (1910): Minéralogie de la France et de ses colonies, Librairie Polytechnique, Ch. Béranger Editeur, Tome IV, 900.
Arrondissement of Le Marin Les Trois-Îlets ⓘ Anse à l'Âne	[Opal] Robertson Collection
Sainte-Anne ⓘ Savane des Pétrifications	[Opal] Lacroix, A. (1910): Minéralogie de la France et de ses colonies, Librairie Polytechnique, Ch. Béranger Editeur, Tome III, 137-138.
New Caledonia Northern Province ⓘ Diahot River Valley	[Opal] Briggs, R. M. (1975). Structure, metamorphism and mineral deposits in the Diahot region, northern New Caledonia (Doctoral dissertation, ResearchSpace@ Auckland).
Houaïlou ⓘ Poro Mine	[Opal] Berger, V.I., Singer, D.A., Bliss, J.D., and Moring, B.C., 2011, Ni-Co laterite deposits of the world; database and grade and tonnage models: U.S. Geological Survey Open-File Report 2011-1058.
Ouégoa ⓘ Fern Hill Mine	[Opal] Briggs, R. M. (1975). Structure, metamorphism and mineral deposits in the Diahot region, northern New Caledonia. Thesis (PhD-Geology), University of Auckland, 1975.
Pouembout ⓘ Népoui Mine	[Opal] Berger, V.I., Singer, D.A., Bliss, J.D., and Moring, B.C., 2011, Ni-Co laterite deposits of the world; database and grade and tonnage models: U.S. Geological Survey Open-File Report 2011-1058.
Southern Province Yaté ⓘ Goro Mine	[Opal] Berger, V.I., Singer, D.A., Bliss, J.D., and Moring, B.C., 2011, Ni-Co laterite deposits of the world; database and grade and tonnage models: U.S. Geological Survey Open-File Report 2011-1058.
Normandy Manche ⓘ Cherbourg	[Opal] Yale Peabody Museum
Nouvelle-Aquitaine ⓘ Charente-Maritime	[Amber] NÉRAUDEAU D., PERRICHOT V., DEJAX J., MASURE E., NEL A., PHILIPPE M., MOREAU P., GUILLOCHEAU F. & GUYOT T. 2002. — Un nouveau gisement à ambre insectifère et à végétaux (Albien terminal probable) : Archingeay (Charente-Maritime, France). Geobios 35: 233-240.
Corrèze Ussel Meymac ⓘ La Grange Mine	[Opal-A var: Opal-AN] Ansermet, S., Cuchet, S. & Meisser, N. (2010): Minéralogie de la mine de La grange, Meymac, Corrèze. Le Règne Minéral, 91: 23-31
Deux-Sèvres Bressuire Mauléon Le Temple ⓘ La Commanderie mine	[Opal] Le Cahier des micromonteurs, 2002, N°75, pp 8-25
Dordogne Bergerac ⓘ Le Buisson-de-Cadouin	[Opal] Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp.
Nontron Saint-Pardoux-la-Rivière ⓘ Le Manderau (Le Mandereau; Le Mandaraud)	[Opal] BRGM survey data
Haute-Vienne Limoges Saint-Sylvestre ⓘ Fanay Mine	[Opal] J. Geffroy, J.A. Sarcia, J. Chervet : "Les Minéraux Uranifères Français", 1960, Institut National des Sciences et Techniques Nucléaires / Saclay - PUF.
Lot-et-Garonne ⓘ Coutras deposit	[Opal] Econ Geol (1989) 84:1541-1556
Occitanie Aveyron Villefranche-de-Rouergue Firmi ⓘ Puy de Wolf (Puech de Voll)	[Opal]
Gard Le Vigan Alzon ⓘ ~~Valcroze~~	[Opal-A var: Opal-AN] Patrice Queneau Collection
Haute-Garonne Saint-Gaudens Moncaup ⓘ Moncaup S.S.1	[Opal] Inventaire Minéralogique de la France numéro 8 Haute Garonne 31 Editions du BRGM 1978 page 115
ⓘ Hérault	[Opal] TREILLARD Michel collection
Béziers ⓘ Caux	[Opal] collection bernard bouissac
Lodève ⓘ Fontès	[Opal] collection bernard bouissac
Le Bosc ⓘ Riviéral	[Opal] "Giorgio Bortolozzi (visual identification)"
Le Puech ⓘ Rabejac Est	[Opal] Giorgio Bortolozzi visual identification
Pyrénées-Orientales Céret Collioure ⓘ Pegmatite field	[Opal] BERBAIN. C, RILEY. T, FAVREAU. G, (2012) Phosphates des pegmatites du massif des Albères. Ed Association Française de Microminéralogie
Prades Mosset ⓘ Mosset rare earths deposit	[Opal-A var: Opal-AN] Remy, P., Gatel, P., Meisser, N. (2014): Indice à terres rares de Mosset (Pyrénées-Orientales). Le Cahier des Micromonteurs, 1-2014, 3-17.
Tarn Castres Fontrieu Fumade ⓘ Phosphate occurrence	[Opal] Jean-Marie LAURENT's collection
Pays de la Loire Loire-Atlantique Nantes Indre ⓘ Haute-Indre	[Opal] Baret, Ch. (1905): Catalogue de la Collection de Minéralogie de la Loire-Inférieure, Muséum de Nantes, 92.
ⓘ Le Loroux-Bottereau	[Opal] Baret, Ch. (1905): Catalogue de la Collection de Minéralogie de la Loire-Inférieure, Muséum de Nantes, 86.
Vendée Les Sables-d'Olonne ⓘ La Garnache	[Amber] Vincent Perrichot 2014, Paleontoretaceous Vendean amber (northwestern France)
Provence-Alpes-Côte d'Azur Alpes-Maritimes Grasse ⓘ Biot	[Opal] Fröhlich F., Mari G., Mari D. (2001), Les silicifications hydrothermales à opale de Biot (Alpes-Maritimes), Le Règne Minéral, n°40, pp: 5-12
Nice Saint-Etienne-de-Tinée ⓘ ~~Claï~~	[Opal] Chollet Pascal Collection
Var Draguignan Fréjus ⓘ Les Trois Termes outcrop	[Opal] S. MAURY (S), 2015 - Les indices minéralogiques de l'Estérel, 1ère partie. Le Cahier des Micromonteurs, n°128 (2-2015), pp 17-33
Saint-Raphaël Agay ⓘ Le Gratadis ravine	[Opal-A var: Opal-AN] MAURY (S), 2016 - Les indices minéralogiques de l'Estérel, 2ème partie. Le Cahier des Micromonteurs, n°132 (2-2016), pp 5-27
ⓘ Le Mal-Infernet ravine	[Opal] MAURY (S), 2015 - Les indices minéralogiques de l'Estérel, 1ère partie. Le Cahier des Micromonteurs, n°128 (2-2015), pp 17-33
Vaucluse Apt ⓘ Courgas ravine	[Opal] F. Roulin et al. , 1986, 109, pp. 349-357.
ⓘ Réunion	[Opal] [Hey p438]
Saint-Paul ⓘ Maïdo	[Opal-A var: Opal-AN] collection Joachim Esche

Georgia
Adjara ⓘ Goderdzi Petrified Forest Natural Monument	[Opal] Alexander G. Tvalchrelidze, Georges Morizot (2003) Mineral Resource Base of the Southern Caucasus and Systems for its Management in the XXIst Century. Springer 204pp
Kvemo Kartli Bolnisi District ⓘ Madneuli Mine	[Opal] Ramaz Migineishvili (2005) Hybrid nature of the Madneuli Cu-Au deposit, Georgia. IGCP Project 486, 2005 Field Workshop, Kiten, Bulgaria, 14-19 September 2005

Germany
Baden-Württemberg Freiburg Region Breisgau-Hochschwarzwald Badenweiler Schweighof ⓘ Klemmbach quarry (Schweighof quarry)	[Opal-A var: Opal-AN] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Bötzingen ⓘ Fohberg Quarry (Hauri Quarry)	[Opal-A var: Opal-AN] Fricke, G., (1988): Der Kaiserstuhl und seine Minerale, Der Aufschluss, Vol. 39(2), 74-76
ⓘ Eisenbach	[Opal-A var: Opal-AN] Walenta, K. (1992) Die Mineralien des Schwarzwaldes und ihre Fundstellan. Christian Weise Verlag, München, 336 pages [in German].
Ihringen ⓘ Föhrenberg	[Opal-A var: Opal-AN] Aufschluss 1988(2), 76
Vogtsburg im Kaiserstuhl Burkheim ⓘ Humberg quarries	[Opal-A var: Opal-AN] No reference listed
Oberbergen ⓘ Pulverbuck	[Opal] Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Oberrotweil ⓘ Kirchberg Quarry	[Opal-A var: Opal-AN] Fricke, G., (1988): Der Kaiserstuhl und seine Minerale, Der Aufschluss, Vol. 39(2), 74-76
Emmendingen Sasbach am Kaiserstuhl ⓘ Eichert	[Opal-A var: Opal-AN] Bega photo
ⓘ Limberg Quarries	[Opal-A var: Opal-AN] No reference listed
Freiburg im Breisgau Schauinsland ⓘ Roggenbach vein	[Opal-A var: Opal-AN] Weiß, S. (1990) Mineralfundstellen, Deutschland West. Weise (Munich), 320 pgs.
Konstanz Singen ⓘ Hohentwiel	[Opal] Lapis 1978(1), 19
Lörrach Malsburg-Marzell ⓘ Malsburg	[Opal-A var: Opal-AN] Brill, A. R. (2011): Die Malsburger Granitsteinbrüche bei Kandern im südwestlichen Schwarzwald. Lapis 36 (7-8), 43-51; 70.
Schönau im Schwarzwald ⓘ Sengalenkopf	[Opal-A var: Opal-AN] Walenta, K. (1992) Die Mineralien des Schwarzwaldes und ihre Fundstellan. Christian Weise Verlag, München, 336 pages [in German].
Todtnau ⓘ Lisbühl	[Opal-A var: Opal-AN] http://www.mineralienatlas.de/lexikon/index.php/Deutschland/Baden-W%FCrttemberg/Schwarzwald/Todtnau/Lisb%FChl
Ortenaukreis Haslach im Kinzigtal Haslach im Kinzigtal ⓘ Segen Gottes Mine (Gottes Segen Mine; Gottessegen Mine)	[Opal-A var: Opal-AN] Wittern: "Mineralfundorte in Deutschland", 2001; Schmeltzer, H. (1993): Die Grube Segen Gottes bei Schnellingen - ein polymetallisches Mineralvorkommen. Der Erzgräber, 7 (2), 34-35.
Hornberg ⓘ Offenbach valley	[Opal-A var: Opal-AN] Lapis 23(12), 45 (1998)
Oberwolfach ⓘ Clara Mine	[Opal-A var: Opal-AN] Walenta, K. (1992): Die Mineralien des Schwarzwaldes. Chr. Weise Verlag, München, 336 pp. (in German)
Waldshut St Blasien Menzenschwand Vorderdorf ⓘ Granite quarry (Schleifbach quarry)	[Opal-A var: Opal-AN] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Waldshut-Tiengen Detzeln ⓘ Porphyry quarry	[Opal-A var: Opal-AN] Hess, E., Graeser, S. & Gabriel, W. (2011): Das Porphyrwerk Detzeln im Steinatal und seine Mineralien. Lapis 36 (4), 25-35; 54.
Karlsruhe Region Freudenstadt Bad Rippoldsau-Schapbach Wildschapbach valley ⓘ Friedrich-Christian Mine	[Opal-A var: Opal-AN] Walenta, K. (1992) Die Mineralien des Schwarzwaldes und ihre Fundstellan. Christian Weise Verlag, München, 336 pages [in German].
Rhein-Neckar-Kreis Schriesheim Ursenbach ⓘ Ursenbach Mine	[Opal-A var: Opal-AN] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Wiesloch ⓘ Schwetzinger Straße slag locality	[Opal] Himmel, H. & Müller, K. (1933): Mineralneubildungen in Schlacken von Wiesloch (Baden). Geologische Rundschau 23a (Sonderband Festschrift Wilhelm-Salomon-Calvi), 7-12.
Bavaria Lower Bavaria Freyung-Grafenau District Röhrnbach ⓘ Steinerleinbach Quarry	[Opal-A var: Opal-AN] Habel, M. (2009): Der Granodioritbruch der Fa. Josef Uhrmann OHG, Steinerleinbach bei Röhrnbach. Mineralien-Welt 20 (2), 66-86.
Passau District Untergriesbach ⓘ Ficht Mine	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
ⓘ Grögöd Quarry (G'steinert Quarry)	[Opal-A var: Opal-AN] Mineralien-Welt 18 (5) (2007) 20-26.
ⓘ Steinhag marble quarry	[Opal] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Vilshofen ⓘ Wimhof Quarry	[Opal] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Regen District Bodenmais ⓘ Silberberg Mine	[Opal] Obermüller, T., (1993): Der Silberberg bei Bodenmais/Bayer. Wald, Der Aufschluss, Vol. 44, 201-224
Lower Franconia Aschaffenburg District Sailauf Hartkoppe ⓘ Fuchs Quarry	[Opal] see locality page
Haßberge District Maroldsweisach ⓘ Zeilberg Quarry	[Opal-A var: Opal-AN] Wittern: "Mineralfundorte in Deutschland", 2001
Upper Franconia Hof District Köditz ⓘ Siebenhitz	[Opal-A var: Opal-AN] F. Müller: "Bayerns steinreiche Ecke", 2nd ed., Oberfränkische Verlagsanstalt und Druckerei GmbH (Hof), 1984
Rehau Wurlitz ⓘ Heß quarry	[Opal-A var: Opal-AN] Rost, F. (1949): Contributions to Mineralogy and Petrology 1(5/6), 627-688.
Wunsiedel im Fichtelgebirge Arzberg ⓘ Arzberg iron mines	[Opal] Meier, S. (2017): Rhodochrosit aus dem Fichtelgebirge: Der Bergbau von Arzberg. Lapis, 42 (3), 16-24; 54.
Kirchenlamitz ⓘ Epprechtstein	[Opal-A var: Opal-AN] Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Weißenstadter Forst-Nord ⓘ Streuspitz	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Wunsiedel Schönbrunn ⓘ Acherwiese	[Opal] F. Müller: "Bayerns steinreiche Ecke", 2nd. ed. (1984), pp. 59-62
Upper Palatinate Amberg-Sulzbach District Auerbach in der Oberpfalz Schleichershof ⓘ Leonie I Mine	[Opal-A var: Opal-AN] peter neschen collection
Cham District Wald Roßbach ⓘ Himmelleiten Quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Neustadt an der Waldnaab District Flossenbürg ⓘ Granite quarries	[Opal-A var: Opal-AN] Weiss, S. (1990) Mineralfundstellen Atlas, Deutschland West. Weise Verlag, München, 320 pages.
Waidhaus ⓘ Silbergrube	[Opal-A var: Opal-AN] Rolf Luetcke
Tirschenreuth District Kulmain ⓘ Zinster Kuppe	[Opal-A var: Opal-AN] Weiss, S. (1990) Mineralfundstellen Atlas, Deutschland West. Weise Verlag, München, 320 pages.
Berlin Spandau ⓘ Siemensstadt	[Amber] Michael Meder collection
Brandenburg Barnim Eberswalde Ruhlsdorf ⓘ Gravel quarry	[Amber] A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
Dahme-Spreewald Königs Wusterhausen Niederlehme ⓘ Sand & Mortar works quarry	[Amber] Andreas Gerstenberg collection
Märkisch-Oderland Bad Freienwalde ⓘ Clay pit	[Amber] Andreas Gerstenberg collection
Rüdersdorf bei Berlin ⓘ Limestone quarries	[Amber] Jahn, S. (2013): Der Kalksteinbruch Rüdersdorf bei Berlin. Mineralien-Welt 24 (3), 44-88.
Hesse Darmstadt Bergstraße Bensheim Hochstädten ⓘ Linck marble works	[Opal] Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Gorxheimertal Gorxheim ⓘ Goldloch Shaft	[Opal] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Lautertal (Odenwald) Raidelbach Katzenstein ⓘ Point 18.0	[Opal] Collection of Steffen Michalski, ex-collection and collected by Klaus PETITJEAN
Reichenbach Borstein ⓘ Point 6.1	[Opal] Collection of Steffen Michalski, ex-collection and collected by Klaus PETITJEAN
Hohenstein ⓘ Point 16.1	[Opal-A var: Opal-AN] No reference listed
Darmstadt-Dieburg Otzberg ⓘ Hering	[Opal] Nickel, E., and Fettel, M. (1985): Odenwald. Sammlung geologischer Führer Vol. 65, 2nd ed., Bornträger (Berlin, Stuttgart), 231 pp.
Roßdorf ⓘ Roßberg Quarry	[Opal-A var: Opal-AN] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Frankfurt ⓘ Bockenheim	[Opal] Jordan, J. L. (1803) Mineralogische berg- und hüttenmännische Reisebemerkungen vorzüglich in Hessen, Thüringen, am Rheine und im Sayn-Altenkirchner Gebiete gesammelt. 288 pp +Tafeln, Göttingen.
Main-Kinzig-Kreis Hanau ⓘ Großauheim	[Opal-A var: Opal-AN] S. Weiss: Mineralfundstellen Deutschland West, Weise (Munich), 1990
Neuberg ⓘ Rüdigheim	[Opal-A var: Opal-AN] Collection of Volker Betz
Odenwaldkreis Reichelsheim ⓘ Ober-Ostern	[Opal] S. Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Offenbach Mühlheim am Main Dietesheim ⓘ Basalt quarries	[Opal-A var: Opal-AN] S. Weiss: Mineralfundstellen, Deutschland West, Weise (Munich), 1990
Wetteraukreis Butzbach ⓘ Griedel	[Opal] https://www.zobodat.at/pdf/Ber-Oberhess-Ges-Natur-u-Heilkde_3_0138-0141.pdf
Echzell Bingenheim ⓘ Basalt quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Nidda ⓘ Hohenstein quarry	[Opal-A var: Opal-AN] Ehrenberg, K. H. Hentschel, G. Schricke, W. & Strecker, G. (1982) Vogelsberg-Vulkanismus. Fortschr. Mineral. 60, Beih. 2, 17-42.
Oberwiddersheim ⓘ Nickel quarry (Oberwiddersheim quarry)	[Opal-A var: Opal-AN]
Reichelsheim Blofeld ⓘ Basalt quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Giessen Region Giessen Biebertal Rodheim-Bieber ⓘ Dünsberg	[Opal] Weiss, S. (1990) Mineralfundstellen Atlas, Deutschland West. Weise Verlag, München, 320 pages.
Buseck Großen-Buseck ⓘ Attenberg quarry	[Opal] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Hungen Langd ⓘ Maykranz Quarry	[Opal-A var: Opal-AN]
Laubach Gonterskirchen ⓘ Basalt quarry	[Opal] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Pohlheim Hausen ⓘ Schiffenberg quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Rabenau Londorf ⓘ Kahlenberg quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Vogelsbergkreis Herbstein ⓘ Herbstein basalt quarry (Schrimpf basalt quarry)	[Opal-A var: Opal-AN]
Homberg Nieder-Ofleiden ⓘ Hochberg quarry (Hohenberg quarry)	[Opal] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Lower Saxony Celle District Faßberg ⓘ Niederohe (Nieder-Ohe)	[Opal] Reinsch, D. (1985) Lagerstätten mineralischer Rohstoffe im Braunschweiger Land. Clausthaler Geologische Abhandlungen. Sonderband Nr.4.
ⓘ Oberohe (Ober-Ohe)	[Opal] Reinsch, D. (1985) Lagerstätten mineralischer Rohstoffe im Braunschweiger Land. Clausthaler Geologische Abhandlungen. Sonderband Nr.4.
Goslar District Braunlage ⓘ St Andreasberg	[Opal] No reference listed
ⓘ Roter Bär Mine	[Opal] SEM-EDS and Wet Chemical by Joy Desor, Gerhard Möhn
Clausthal-Zellerfeld Oberschulenberg ⓘ Glücksrad Mine	[Opal] Lapis, 11 (1), 9-18+42
Goslar ⓘ Großfürstin Alexandra Mine	[Opal] Dietrichs, J. (2006): Die Mineralien der Nickelgrube "Großfürstin Alexandra" im Ostharz. Lapis 31 (6), 28-30; 70.
Göttingen District Adelebsen ⓘ Bramburg Quarry	[Opal] Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Mecklenburg-West Pomerania Vorpommern-Greifswald Usedom Island Loddin ⓘ Stubbenfelde	[Amber] A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
North Rhine-Westphalia Arnsberg Siegen-Wittgenstein Neunkirchen Hohenseelbachskopf ⓘ Basalt quarry	[Opal] Haege, T. (1887): Die Mineralien des Siegerlandes und der angrenzenden Gebiete. 50 pp.
Salchendorf ⓘ Basanite quarry	[Opal-A var: Opal-AN] Klein, E. (1999): Ein Basanit-Vorkommen nordwestlich von Salchendorf bei Neunkirchen / Siegerland. Der Aufschluss, 50, 203-206.
Cologne Aachen Alsdorf ⓘ Anna mine	[Opal] T. Witzke, F. de Wit, U. Kolitsch and G. Blaß (2015): Mineralogy of the Burning Anna I Coal Mine Dump, Alsdorf, Germany. Chapter 7, 203-240; in: Stracher, G. B., Prakash, A. and Sokol, E. V.: Coal and Peat Fires: A Global Perspective, Volume 3: Case Studies - Coal Fires, Elsevier.
Bonn Bad Godesberg ⓘ Lyngsberg (Lühnsberg; Lünsberg)	[Opal-A var: Opal-AN] Brauns, R. (1922): Die Mineralien der Niederrheinischen Vulkangebiete, Schweitzerbart Stuttgart
ⓘ Finkenberg	[Opal] Brauns, R., (1922): Die Mineralien der Niederrheinischen Vulkangebiete, Schweizerbart, Stuttgart
Oberkassel (Obercassel) ⓘ Rabenlay (Rabenley)	[Opal] Dechen, H. von (1852): Geognostische Beschreibung des Siebengebirges am Rhein, Cohen Bonn
Rhein-Sieg-Kreis Königswinter ⓘ Quegstein	[Opal] Andreas Gerstenberg collection
ⓘ Stenzelberg	[Opal] Brauns, R., (1922): Die Mineralien der Niederrheinischen Vulkangebiete, Schweizerbart, Stuttgart
ⓘ Weilberg (Großer Weilberg)	[Opal] Brauns, R., (1922): Die Mineralien der Niederrheinischen Vulkangebiete, Schweizerbart, Stuttgart
Rhineland-Palatinate Donnersbergkreis Winnweiler Imsbach ⓘ Grüner Löwe Mine	[Opal] Lapis, 9 (5), 36-39.
ⓘ Katharina I Mine	[Opal] Lapis, 9 (5), 36-39.
ⓘ Katharina II Mine	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ Weiße Grube	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Kusel Kusel-Altenglan Reichweiler ⓘ Karrenberg Quarry	[Opal] MÜLLER, G. (1990): Mineralisationen vom Karrenberg bei Reichweiler (Kreis Kusel).- Der Aufschluss, 41 (H. 5), S. 299-311.
Lauterecken-Wolfstein Hinzweiler ⓘ Hohe Buche	[Opal] Weiss (1990) Mineralfundstellen, Deutschland West. Weise (Munich).
Mayen-Koblenz Mendig Bell ⓘ Rothenberg Quarry	[Opal] Hentschel, G., Die Mineralien der Eifelvulkane, Weise Verlag, München (2. Auflage), 1987
Mendig ⓘ In den Dellen quarries	[Opal] Hentschel, G., Die Minerale in Auswürflingen des Laacher -See –Vulkans, Der Aufschluss, SB 33, 65-105, 1990
ⓘ Thelenberg	[Opal] Hentschel, G., Die Minerale in Auswürflingen des Laacher -See –Vulkans, Der Aufschluss, SB 33, 65-105, 1990
Wingertsberg ⓘ Pumice quarries	[Opal] Hentschel, G., Die Minerale in Auswürflingen des Laacher -See –Vulkans, Der Aufschluss, SB 33, 65-105, 1990
Pellenz Kruft ⓘ Krufter Ofen	[Opal] Hentschel, G., Die Minerale in Auswürflingen des Laacher -See –Vulkans, Der Aufschluss, SB 33, 65-105, 1990
Vordereifel Ettringen ⓘ Caspar quarry	[Opal-A var: Opal-AN] Blass, G., Graf, H.W., Neufunde von bekannten Fundorten (VI), Mineralien-Welt 3/6,32-35, 1992
Neuwied Unkel Rheinbreitbach ⓘ Virneberg Mine	[Opal] Weiss: "Mineralienfundstellen, Deutschland West", Weise (Munich), 1990
Rhein-Lahn-Kreis Diez Steinsberg ⓘ Steinsberg quarry	[Opal-A var: Opal-AN] S. Weiß: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
Vulkaneifel Daun Oberstadtfeld ⓘ Kahlenberg	[Opal-A var: Opal-AN] Hentschel, G., Die Mineralien der Eifelvulkane, Weise Verlag München (2. Auflage), 1987
Üdersdorf ⓘ Emmelberg	[Opal-A var: Opal-AN] ko.jansen
Gerolstein Hillesheim ⓘ Graulay quarry	[Opal-A var: Opal-AN] Blaß, G. & Kruijen, F. (2013): Die Mineralogischen Neuigkeiten aus der Vulkaneifel. Mineralien-Welt 24 (3), 33-41.
ⓘ Kyller Höhe	[Opal-A var: Opal-AN] Hentschel, G.(1987): Die Mineralien der Eifelvulkane, Weise Verlag München, 2. Auflage
Hohenfels-Essingen ⓘ Feuerberg	[Opal] Blass, G., Graf , HW., Neue Mineralienfunde aus der Vulkaneifel, MW 1/2001
Oberehe-Stroheich ⓘ Döhmberg	[Opal-A var: Opal-AN] Hentschel, G., Die Mineralien der Eifelvulkane, Weise Verlag München (2. Auflage), 1987
Walsdorf ⓘ Goßberg	[Opal-A var: Opal-AN] Hentschel, G.(1987): Die Mineralien der Eifelvulkane, Weise Verlag München, 2. Auflage
Saarland Sankt Wendel Nonnweiler Kastel ⓘ Kloppberg Quarry	[Opal] Thomas Kleser & Erwin Ecker Collections
Saxony-Anhalt Anhalt-Bitterfeld ⓘ Bitterfeld-Wolfen	[Amber] Rappsilber, I. (2022): Bitterfelder Bernstein - Geschichte, Vielfalt, Entstehung. Ampyx-Verlag Dr. A. Stark, Halle (Saale), Germany, 323 pp. (in German).
Bitterfeld ⓘ Goitzsche open cast	[Amber] [www.johnbetts-fineminerals.com]; Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.
Burgenlandkreis Hohenmölsen ⓘ Profen Nord opencast	[Amber] Krumbiegel, G., Wimmer, R., and Cosmowska-Ceranowicz, B. (2010) A new Krantzite find south of Leipzig (the Profen open-cast mine). In: AMBERIF 2010 - Amber in Geology and Archaeology, 17th Seminar, Gdańsk-Warsaw, 10-14; Wimmer, R., Krumbiegel, G., Cosmowska-Ceranowicz, B., and Wagner-Wysiecka, E. (2017) Neufunde von fossilen Harzen aus dem Mitteldeutschen Braunkohlenrevier. Mauritiana (Altenburg), 31, 164-176.
Harz Harzgerode Güntersberge ⓘ Hirschbüchenkopf Mine	[Opal] Thomas Lühr
Quedlinburg Gernrode Hagental ⓘ Hohe Warte Mine	[Opal] Thomas Lühr collection
Wernigerode Hasserode ⓘ Das Aufgeklärte Glück Mine (Aufgeklärtes Glück Mine)	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ St Georg Mine (Goslar'sche Gleie)	[Opal] Th.Lühr collection
Saalekreis Petersberg ⓘ Goethe Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ Petersberg Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Saxony ⓘ Annaberg mining district	[Opal] Lapis 17(12), 24-33
Bautzen District Oßling ⓘ Oßling Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Wittichenau ⓘ Dubring Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Erzgebirgskreis Bärenstein Niederschlag ⓘ Straßburger Glück Mine	[Opal] Lapis, 19 (4), 13-22+50.
Breitenbrunn Antonsthal ⓘ Shaft 235	[Opal] Gröbner J., Kolitsch U.; Neufunde aus dem Erzgebirge (II), Mineralien-Welt Jg 17 (2006), 3, pag. 22-27.
Ehrenfriedersdorf ⓘ Sauberg Mine	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ Eibenstock	[Opal] Frenzel, A. (1874): Mineralogisches Lexicon fpr das Königreich Sachsen, Leipzig.
Blauenthal ⓘ Fahsel quarry	[Opal] Tröger, S. (2009): Der Steinbruch Fahsel im Eibenstocker Granit, Westerzgebirge. Lapis 34 (6), 49-52.
Sosa Riesenberg ⓘ Friedrich August adit	[Opal] Lapis 33 (10), 38-40.
ⓘ Johanngeorgenstadt	[Opal] Frenzel, A. (1874): Mineralogisches Lexicon für das Königreich Sachsen, Leipzig.
Steinbach ⓘ Himmelfahrt Mine	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
Schneeberg Neustädtel ⓘ Wald Shaft	[Opal] Lapis 30(7/8):77 (2005)
Schwarzenberg ⓘ Pöhla-Tellerhäuser Mine	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ Prospect 24	[Opal] Andreas Gerstenberg collection
Görlitz District ⓘ Königshain	[Opal-A var: Opal-AN] www.minmax.net
Neißeaue ⓘ Emmerichswalde	[Opal] Witzke, T. & Giesler, T. (2013): Seltene Phosphate und Vanadate von Emmerichswalde bei Görlitz/Sachsen. Mineralien-Welt 24 (2), 40-55
Rengersdorf ⓘ Field near the Hochstraße	[Opal-A var: Opal-AN] T. Witzke & T. Giesler (1993): Dufrenit und Opal von Rengersdorf/Lausitz.- Mineralien-Welt 4 (5), 14
Mittelsachsen Brand-Erbisdorf ⓘ Vereinigt Feld Mine	[Opal] August Frenzel (1874): Mineralogisches Lexicon fpr das Königreich Sachsen, Leipzig.
Claußnitz Diethensdorf ⓘ Diethensdorf Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001
ⓘ Freiberg	[Opal] Lapis 11(7/8), 13-60 (1986)
Hartmannsdorf ⓘ Ratssteinbruch	[Opal] Vollstädt, H. (1979): Einheimische Minerale, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, p. 289.
ⓘ Leisnig	[Opal] H. Vollstädt, R. Baumgärtel: "Einheimische Edelsteine", 2nd. ed., Steinkopff (Dresden), 1977
Sächsische Schweiz-Osterzgebirge Altenberg ⓘ Tin mine	[Opal] Mineralien-Welt, (2), 17-39.
Vogtlandkreis Lengenfeld Pechtelsgrün ⓘ Wolframite mine	[Opal] Lapis, 17 (7/8), 26-33+90
ⓘ Tirpersdorf	[Opal-A var: Opal-AN] Gröbner, J. and Kolitsch, U. (2007): The minerals of the uranium prospect at Tirpersdorf, Vogtland. Lapis 32, 37-42; 58. (in German)
Schleswig-Holstein Herzogtum Lauenburg Groß Pampau ⓘ Ohle & Lau gravel pit	[Amber] A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
Nordfriesland ⓘ Sankt Peter-Ording	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).; Wittern, A. (2001) Mineralfundorte in Deutschland. Schweizerbart (Stuttgart).
Sylt Island Kampen ⓘ Rotes Kliff	[Amber] A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
Plön Preetz ⓘ Gravel works	[Opal] A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
Thuringia Greiz District Ronneburg ⓘ Lichtenberg open cast	[Amber] Andreas Gerstenberg collection
Weida ⓘ Loitsch Quarry	[Opal] Richter, E. & Rüger, F. (2010): Der Diabas-Tagebau Loitsch in Thüringen und seine Mineralien. Lapis 35 (2), 13-22; 54.
Saale-Orla District Wurzbach Weitisberga ⓘ Henneberg Quarry	[Opal] Wittern: "Mineralfundorte in Deutschland", 2001

Greece
Attica East Attica Lavreotiki Lavrion Mining District Agios Konstantinos (Kamariza) ⓘ Kamariza mines (Kamareza mines)	[Opal-A var: Opal-AN] Ritter, K.-H. (1978): Hyalit und Langit von Lavrion. Lapis, 3(10), 11.
Plaka Paliokamariza Mines (Paleokamariza Mines) ⓘ Paliokamariza Mine No. 18	[Opal-A var: Opal-AN] Branko Rieck collection
Central Macedonia Chalkidiki Polygyros ⓘ Ormylia mine	[Opal] Sideridis, Alkiviadis, Petros Koutsovitis, Basilios Tsikouras, Christos Karkalis, Christoph Hauzenberger, Federica Zaccarini, Pavlos Tsitsanis, Christina Vasiliki Lazaratou, Vasilios Skliros, Dionisios Panagiotaras, Dimitrios Papoulis, and Konstantin Hatzipanagiotou. (2022) "Pervasive Listwaenitization: The Role of Subducted Sediments within Mantle Wedge, W. Chalkidiki Ophiolites, N. Greece" Minerals 12, no. 8: 1000. https://doi.org/10.3390/min12081000
ⓘ Vavdos mine	[Opal] Sideridis, Alkiviadis, Petros Koutsovitis, Basilios Tsikouras, Christos Karkalis, Christoph Hauzenberger, Federica Zaccarini, Pavlos Tsitsanis, Christina Vasiliki Lazaratou, Vasilios Skliros, Dionisios Panagiotaras, Dimitrios Papoulis, and Konstantin Hatzipanagiotou. (2022) "Pervasive Listwaenitization: The Role of Subducted Sediments within Mantle Wedge, W. Chalkidiki Ophiolites, N. Greece" Minerals 12, no. 8: 1000. https://doi.org/10.3390/min12081000
Eastern Macedonia and Thrace Evros Alexandroupoli ⓘ Perama Hill deposit	[Opal] Voudouris, P., Papavassiliou, C., Alfieris, D., & Falalakis, G. (2007). Gold-silver tellurides and bismuth sulfosalts in the high-intermediate sulfidation Perama Hill deposit, western Thrace (NE Greece). Geol Survey Finland Guide, 53, 77-84.
Rhodope Maroneia-Sapes ⓘ Mavrokoryfi prospect	[Opal] Vodouris, P. C. (2011): Conditions of formation of the Mavrokoryfi high-sulfidation epithermal Cu–Ag–Au–Te mineralization (Petrota Graben, NE Greece). Mineralogy and Petrology 101, 97-113.; Voudouris, P. (2005). Mineralogy of the high-sulfidation Cu-Sb-Te Mavrokoryfi prospect (western Thrace, Greece). In Mineral Deposit Research: Meeting the Global Challenge (pp. 1435-1438). Springer, Berlin, Heidelberg.
Ionian Islands Lefkada Lefkada island ⓘ Agios Petros	[Opal] Stamatakis, M., and Hein, J.R. (1993) Origin of barite in Tertiary marine sedimentary rocks from Lefkas Island, Greece. Economic Geology, 88, 91-103.
ⓘ Kastos island	[Opal] Bourli, Nicolina, Maria Kokkaliari, Nikolaos Dimopoulos, Ioannis Iliopoulos, Elena Zoumpouli, George Iliopoulos, and Avraam Zelilidis. (2021) "Comparison between Siliceous Concretions from the Ionian Basin and the Apulian Platform Margins (Pre-Apulian Zone), Western Greece: Implication of Differential Diagenesis on Nodules Evolution" Minerals 11, no. 8: 890. https://doi.org/10.3390/min11080890
North Aegean Lesbos ⓘ Mytilene	[Opal-A var: Opal-AN] Christophos
Samos Eastern Samos ⓘ Mytilinii Basin	[Opal] Helvaci, C., Stamatakis, M. G., Zagouroglou, C., & Kanaris, J. (1993). Borate minerals and related authigenic silicates in northeastern Mediterranean Late Miocene continental basins. Exploration and Mining Geology, 2(2), 171-178.
Western Samos ⓘ Karlovassi basin	[Opal] Econ Geol (1989)84:788-798
South Aegean Milos Kimolos Kimolos Island ⓘ Prassa Quarry (Bentomine S.A. Quarry)	[Opal] Godelitsas, A.; Gamaletsos, P.& Roussos-Kotsis, M.(2010): Mordenite-bearing tuffs from Prassa quarry, Kimolos island, Greece. European Journal of Mineralogy. 22, 797-811
Milos Island ⓘ Chondro Vouno	[Opal-A var: Opal-AN] No reference listed
ⓘ Paliochori beach (Paleochori bay)	[Opal] Balić-Žunić, T., Garavelli, A., Jakobsson, S. P., Jonasson, K., Katerinopoulos, A., Kyriakopoulos, K., & Acquafredda, P. (2016). Fumarolic minerals: An overview of active European volcanoes. In Updates in Volcanology-From Volcano Modelling To Volcano Geology. InTechOpen.
ⓘ Profitis Ilias Au deposit	[Opal] Kilias, S.P., Naden, J., Cheliotis, I., Shepherd, T.J., Constandinidou, H., Crossing, J., and Simos, I. (2001): Mineralium Deposita 36, 32-44.
Thira Santorini Island Santorini Caldera ⓘ Nea Kameni Island	[Opal] Balić-Žunić, T., Garavelli, A., Jakobsson, S. P., Jonasson, K., Katerinopoulos, A., Kyriakopoulos, K., & Acquafredda, P. (2016). Fumarolic minerals: An overview of active European volcanoes. In Updates in Volcanology-From Volcano Modelling To Volcano Geology. InTechOpen.
Thessaly Larissa Elassona ⓘ Sarantaporo-Elassona basin	[Opal] M.G. Stamatakis, N.K. Koukouzas (2001) The occurrence of phosphate minerals in lacustrine clayey diatomite deposits, Thessaly, Central Greece. Sedimentary Geology 139:33-47.
Western Greece Achaea West Achaea ⓘ Araxos	[Opal] Pe-Piper, Georgia, David J.W. Piper, Nicolina Bourli, and Avraam Zelilidis. (2021) "Evolution of Sedimentary Basins as Recorded in Silica Concretions: An Example from the Ionian Zone, Western Greece" Minerals 11, no. 7: 763. https://doi.org/10.3390/min11070763

Greenland
Avannaata Nuussuaq Peninsula Niaqornat ⓘ Reyerite type locality	[Opal] Petersen, O. V. & Johnsen, O. (2005) Minerals first described from Greenland. The Canadian Mineralogist- Special Publication: 8, 184p.
Kujalleq Igaliku Narsaarsuk Plateau ⓘ Narssârssuk pegmatite	[Opal] Knut Eldjarn Collection
Ilímaussaq complex ⓘ Kvanefjeld ?	[Opal] Petersen, O.V., Giester, G., Brandstätter, F., Niedermayr, G. (2002): Nabesite, a new mineral species from the Ilimaussaq alkaline complex. Canadian Mineralogist. 40, 173-181
Qeqertalik Disko Island ⓘ Qarusuit ?	[Opal] Bøggild, O.B. (1953): The Mineralogy of Greenland. Meddelelser om Grønland, Bd. 149. Nr. 3. 445 pages. (p. 352)

Honduras	[Opal] Rocks & Minerals (xxxx) 54, 266.; Gübelin, E., Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).; Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.

Gracias a Dios Department ⓘ Gracias a Dios Mine	[Opal] Rob Lavinsky specimen
Lempira Department ⓘ Erandique	[Opal] Prüfer, P. (2002): Basalt-Opal aus Honduras. Lapis 27 (4): 35
ⓘ Tablon Mine	[Opal] Wayne Osborne Collection
ⓘ Gracias	[Opal] N. Jb. Mineral. Abh. 186 (2009) 11-20.
San Andrés Sosoal ⓘ Las Colinas deposits	[Opal] Sinkankas, J. (1976) Gemstones of North America, vol. 2, p. 67.
Santa Bárbara Department Azacualpa ⓘ San José Lepasite river	[Opal] Sinkankas, J. (1976) Gemstones of North America, vol. 2, p. 67.

Hungary	[Opal] www.giant.net.au/users/bmi/prof.htm. [Link dead July 2019] Gübelin, E. and Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).

Borsod-Abaúj-Zemplén County Gönc District Abaújszántó ⓘ Sulyom Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
ⓘ Süveges Hill	[Opal] Szakáll: Topographia Mineralogica Hungariae
Arka ⓘ Arka Brook Valley	[Opal]
ⓘ Boldogkőváralja	[Opal] Szakáll & Gatter: Hungarian Mineral Species, 1993
ⓘ Borsó Hill	[Opal]
ⓘ Dobogó Hill	[Opal]
ⓘ Fenyőkő Hill	[Opal] Szakáll & Jánosi : Minerals of Hungary, 1995
Fony ⓘ Csonkás	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Golop ⓘ Somos	[Opal-A var: Opal-AN]
Hejce ⓘ Gergely Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Helle dűlő	[Opal-A var: Opal-AN] Koch: Minerals of Hungary, 1985
Kéked ⓘ Hasdát Valley	[Opal] Szakáll & Weiszburg: Telkibánya ( Top. Min. Hun.)
Regéc ⓘ Vár Hill	[Opal] Mineral Species of Hungary, 2005
ⓘ Telkibánya	[Opal] Topographia Mineralogica Hungariae II. Szakáll&Weiszburg
ⓘ Gordon Hill	[Opal]
ⓘ Gyepü Hill	[Opal] Szakáll & Weiszburg: Telkibánya
ⓘ Korpa Hill	[Opal]
ⓘ Medve Hill	[Opal]
ⓘ Ósva Valley	[Opal-A var: Opal-AN] Szakáll-Weiszburg: Telkibánya
ⓘ Sinta Hill	[Opal] Szakáll-Gatter: Hungarian Mineral Species, 1996
Sárospatak District ⓘ Bot-kő	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Csurgókúti Quarry	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Erdőhorváti	[Opal]
ⓘ Agáros Hill	[Opal-A var: Opal-AN]
ⓘ Prücsök Hill	[Opal]
ⓘ Tetőcske	[Opal] Szakáll & Gatter: Hungarian Mineral Species, 1993
ⓘ Vég Hill	[Opal] Koch: Minerals of Hungary, 1985
ⓘ Király Hill	[Opal]
Komlóska ⓘ Bolhás Hill	[Opal]
ⓘ Nagy-Egres Brook	[Opal] Koch: Minerals of Hungary, 1985
ⓘ Szkalka Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Szemince	[Opal]
Sátoraljaújhely District Bózsva ⓘ Fekete Hill	[Opal] Collection of Gábor _Mesics
ⓘ Senyő Valley	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Füzérradvány ⓘ Korom Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Hollóháza ⓘ Ökör Hill	[Opal]
Nagyhuta ⓘ Borzás	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Káváskúti Valley	[Opal-A var: Opal-AN] Szakáll & Jánosi: Minerals of Hungary, 1995
Nyíri ⓘ Kandó Hill	[Opal] Szakáll & Gatter: Hungarian Mineral Species, 1993
Szerencs District Legyesbénye ⓘ Fuló Hill	[Opal-A var: Opal-AN] Szakáll: Top.Min. Hun.
ⓘ Zsidótemető	[Opal] Szakáll: Minerals of Szerencsi Hills (Top. Min. Hun.)
Mád Király Hill ⓘ Suba quarry	[Opal] Society of Economic Geologists Student Chapter University of Miskolc (2018) Short course – Industrial minerals in the NE part of Hungary. Telkibánya November 5–8. 2018.
Megyaszó ⓘ Hosszú Hill	[Opal-A var: Opal-AN]
ⓘ Nagy Répás Hill	[Opal]
ⓘ Tetlinke Ditch	[Opal]
ⓘ Monok	[Opal-A var: Opal-AN] [www.johnbetts-fineminerals.com]
ⓘ Csörgő Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
ⓘ Fekete Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
ⓘ Ingvár	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
ⓘ Kálvária Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae
ⓘ Kaptár Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
ⓘ Pipiske	[Opal] Szakáll: Mineralogica Topographia Hungariae III.
ⓘ Zsebrik	[Opal] Szakáll:Top. Min. Hun.
Rátka ⓘ Hercegköves Hill	[Opal] Szakáll:100 Hungarian Mineral Localities,2004
Szerencs ⓘ Közép Hill	[Opal-A var: Opal-AN] Szakáll: Topographia Mineralogica Hungariae III.
Tokaj District ⓘ Csurgókúti Quarry	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Erdőbénye	[Opal] Koch:Minerals of Hungary
ⓘ Aranyos Valley	[Opal]
ⓘ Ligetmajor	[Opal-A var: Opal-AN] http://geomania.hu/lelohely.php?lelohely=200
ⓘ Mogyorósok	[Opal] Szakáll-Gatter-Szendrei: Minerals of Hungary 2005
ⓘ Mulató Hill	[Opal-A var: Opal-AN]
ⓘ Nagy Hill	[Opal-A var: Opal-AN]
Tarcal ⓘ Kopasz Hill andesite quarry	[Opal-A var: Opal-AN] ; http://www.geomania.hu/lelohely.php?lelohely=328
ⓘ Tolcsva	[Opal] Koch: Minerals of Hungary,1986
ⓘ Rudnok Hill	[Opal] Koch: Minerals of Hungary, 1985
Fejér County Gárdony District Pázmánd ⓘ Zsidó Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1985
Sárszentmiklós ⓘ Tuff Quarry	[Opal] Szakáll: 100 Hungarian Mineral Locality
Székesfehérvár District Kőszárhegy ⓘ Kőszárhegy Quarry	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Heves County Bélapátfalva District ⓘ Mikófalva	[Opal] GEODA 2004
Gyöngyös District ⓘ Bába- kő	[Opal] Mineral Species of Hungary, 2005
ⓘ Gyöngyösoroszi	[Opal]
ⓘ Bagolyvár-Furmin	[Opal]
ⓘ Bánya Hill	[Opal] GEODA 2002
ⓘ Jegykő brook valley	[Opal] Szakáll-Jánosi: Minerals of Hungary,1995
ⓘ Károlyvár	[Opal-A var: Opal-AN] Own found,2006
ⓘ Száraz-patak	[Opal] Book: 100 collecting sites of Hungary
Gyöngyöspata ⓘ Aranyos-bérc & Korlát-bérc	[Opal] http://www.geomania.hu/lelohely.php?lelohely=379
ⓘ Prédikáló-tető	[Opal-A var: Opal-AN] http://www.geomania.hu/lelohely.php?lelohely=323
Gyöngyössolymos ⓘ Asztag kő	[Opal-A var: Opal-AN] Szakáll-Gatter-Szendrei: Hungarian Mineral Species,2006
ⓘ Cserkő Mine	[Opal]
ⓘ Eremény Hill - Bárdos Hill	[Opal-A var: Opal-AN] http://geomania.hu/lelohely.php?lelohely=416
ⓘ Kis Hill	[Opal]
ⓘ Szén-patak Cseternás-bérc	[Opal-A var: Opal-AN] Körmendy Regina (2011): A Cseternás-bérci és Szén-pataki ércesedés nyomon követése (2011. augusztusi, októberi és novemberi kutatások eredményei). Lelőhely 2011/VII. p.8-18
ⓘ Üstökfő	[Opal] MAMIT
ⓘ Gyöngyöstarján	[Opal-A var: Opal-AN] T Ungvári collection
ⓘ Csege brook Valley	[Opal] Geoda, 2003
ⓘ Fajzatpuszta	[Opal] Szakáll-Jánosi: Minerals of Hungary
ⓘ Füledugó Quarry	[Opal-A var: Opal-AN] GEODA/2000, Own found.2006
ⓘ Hársas Hill	[Opal-A var: Opal-AN] http://www.geomania.hu/lelohely.php?lelohely=441
ⓘ Kis-domb	[Opal] GEODA/1997
ⓘ Köves Hill	[Opal] Szakáll-Gatter: Hungarian Mineral Species
Kisnána ⓘ Hátsó Tarnóca Quarry	[Opal-A var: Opal-AN] Dávid Szabó
Markaz ⓘ Mraznica-tető-Sas-kő	[Opal] http://www.mineral.hermuz.hu
Mátraszentimre ⓘ Szent Imre Mine	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Mátraszentlászló ⓘ Oszicsinszki Hill	[Opal] GEODA/2005
Pétervására District Mátraderecske ⓘ Kanázsvár	[Opal] Szakáll-Jánosi: Minerals of Hungary, 1995
Recsk ⓘ Csákány kő	[Opal-A var: Opal-AN] Szakáll - Gatter: Minerals of Hungary
Nógrád County Bercel ⓘ Bercel Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Buják	[Opal] C. Lemanski, Jr. (re-entry of lost Mindat data).
ⓘ Felsőpetény	[Opal-A var: Opal-AN]
ⓘ Mátrakeresztes	[Opal] Mineral Species of Hungary, 2005
ⓘ Szalajkás Hill	[Opal]
Nagylóc ⓘ Nagy-Zsunyi Hill quarry (Zunypuszta quarry)	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Nógrádszakál	[Opal] GEODA 2004
Sámsonháza ⓘ Fehér -kő	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Szanda ⓘ Szanda Hill	[Opal] GEODA 2004
Szurdokpüspöki ⓘ Diatoma Mine	[Opal] Szakáll: 100 Hungarian Mineral Locality, 2004
ⓘ Tolmács	[Opal]
Pest County Szentendre District ⓘ Száraz brook	[Opal] Szakáll: 100 Hungarian Mineral Locality, 2004
Szob District Szokolya Öl Hill ⓘ Jacoby adit	[Opal] Sándor Szakáll (2004): 100 Hungarian mineral localities
Veszprém County ⓘ ~~Ajka District~~	[Amber] Zechmeister, L. (1926): Adatok az ajkait, egy hazai fosszilis gyanta ismeretéhez. Mathematikai és Természettudományi Értesítő, 43, 332-341; Szakáll, S. and Jánosi , M. (1996) Minerals og Hungary. Topographia Mineralogica Hungáriáé IV. Herman Ottó Museum, Miskolc, 1996
Balatonfüred District ⓘ Csopak	[Opal] Kiss, G. & Molnár, F. (2006) Mineralogy And Origin Of Geodes In The Balatonfelvidék Sandstone Formation At Csopak Village, Balaton Highland, Hungary. Acta Mineralogica-Petrographica, Abstract Series 5, Szeged, p54
Tapolca District Nemesgulács ⓘ Gulács Hill	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
ⓘ Csúcs Quarry	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995.
Uzsa ⓘ Láz Hill mine	[Opal] "Giorgio Bortolozzi (visual identification)"
Várpalota District Várpalota ⓘ Inota-Puszta	[Opal] Szakáll & Jánosi: Minerals of Hungary, 1995
Veszprém District ⓘ Szentgál	[Opal] Koch: Minerals of Hungary, 1985
Zala County Keszthely district Cserszegtomaj ⓘ Pajtika Hill	[Opal] Koch: Minerals of Hungary, 1985

Iceland
Eastern Region ⓘ Breiðdalur- Berufjörður area	[Opal] Volker Betz (1981) Famous Mineral Localities: Zeolites From Iceland and the Faeroe Islands. Mineralogical Record 12:5-26
Northeastern Region Skútustaðahreppur Myvatn Krafla Volcano ⓘ Hverir fumerole	[Opal] Mineralogy and bulk geochemistry of a fumarole at Hverir, Iceland: Analog for acid sulfate leaching on Mars Am Min in press
Southern Region Bláskógabyggð Haukadalur geothermal area ⓘ Geysir	[Opal] Jones, B., and Renaut, R.W. (2007) Microstructural changes accompanying the opal-A to opal-CT transition: New evidence from the siliceous sinters of Geysir, Haukadalur, Iceland. Sedimentology, 54, 4, 921-948.
Vestmannaeyjar Vestmannaeyjar archipelago (Westman islands) Heimaey island ⓘ Eldfell	[Opal] Balić-Žunić, T., Garavelli, A., Acquafredda, P., Leonardsen, E., & Jakobsson, S. P. (2009). Eldfellite, NaFe (SO4) 2, a new fumarolic mineral from Eldfell volcano, Iceland. Mineralogical Magazine, 73(1), 51-57.; Balić-Žunić, T., Garavelli, A., Jakobsson, S. P., Jonasson, K., Katerinopoulos, A., Kyriakopoulos, K., & Acquafredda, P. (2016). Fumarolic minerals: An overview of active European volcanoes. In Updates in Volcanology-From Volcano Modelling To Volcano Geology. InTechOpen.
Surtsey Island ⓘ Grillid (Cave S-4)	[Opal] Jacobsson et al (1992) Encrustations from Lava Caves in Surtsey, Iceland. A Preliminary Report: Surtsey Research Progress Report X: 73-78 Reykjevik, Iceland.
ⓘ Unnamed borehole	[Opal] Jakobsson, S. P., & Moore, J. G. (1986). Hydrothermal minerals and alteration rates at Surtsey volcano, Iceland. Geological Society of America Bulletin, 97(5), 648– 659. https://doi.org/10.1130/0016-7606(1986)97<648:HMAARA>2.0.CO;2

India
Andhra Pradesh Uttarandhra Region Visakhapatnam District ⓘ Kodúr Mines	[Opal] Rocks & Min.: 8:7.
Gujarat Surat district ⓘ Tadkeshwar mine	[Amber] http://www.bbc.co.uk/news/science-environment-11618809
ⓘ Vastan Mine	[Amber] http://www.bbc.co.uk/news/science-environment-11618809
Jharkhand East Singhbhum District ⓘ Rakha Cu deposit ?	[Opal] S. G. Tenainkai, A. G. Ugarkar, M. V. Koti and A. Mookherjee (1991) Copper-bearing clay minerals of the oxidized zone of the Rakha-Chapri Block, Singhbhum Copper Belt, India. Proceedings of the Indian Academy of Sciences, Earth and Planetary Sciences, 100, 13-30.
Maharashtra Aurangabad Division ⓘ Aurangabad - Jalna area	[Opal] Philip Bluemner collection
Nashik Division Jalgaon District Sawade Pr Chandsar ⓘ Savda	[Opal] Götze, J.; Hofmann, B.; Machałowski, T.; Tsurkan, M.V.; Jesionowski, T.; Ehrlich, H.; Kleeberg, R.; Ottens, B. (2020) Biosignatures in Subsurface Filamentous Fabrics (SFF) from the Deccan Volcanic Province, India. Minerals 10, 540.
Nashik District Sinnar ⓘ Mahodari quarry	[Opal] White (2008)

Indian Ocean
Carlsberg Ridge Wocan Hydrothermal Field ⓘ Wocan I	[Opal] Wang, Y., Han, X., Petersen, S., Frische, M., Qiu, Z., Li, H., ... & Cui, R. (2017) Mineralogy and trace element geochemistry of sulfide minerals from the Wocan Hydrothermal Field on the slow-spreading Carlsberg Ridge, Indian Ocean. Ore Geology Reviews, 84, 1-19.
ⓘ Wocan II	[Opal] Wang, Y., Han, X., Petersen, S., Frische, M., Qiu, Z., Li, H., ... & Cui, R. (2017) Mineralogy and trace element geochemistry of sulfide minerals from the Wocan Hydrothermal Field on the slow-spreading Carlsberg Ridge, Indian Ocean. Ore Geology Reviews, 84, 1-19.
Central Indian Ridge ⓘ Kairei Vent Field	[Opal] Wang, Yejian, Xiqiu Han, Sven Petersen, Matthias Frische, Zhongyan Qiu, Yiyang Cai, and Peng Zhou. (2018) "Trace Metal Distribution in Sulfide Minerals from Ultramafic-Hosted Hydrothermal Systems: Examples from the Kairei Vent Field, Central Indian Ridge" Minerals 8, no. 11: 526. https://doi.org/10.3390/min8110526
Ninety East Ridge (90° E Ridge; Indian Ridge) D.S.D.P. Leg 26 ⓘ Site 253	[Opal] D. Besse et al. , Bell. Minéral. , 1981, 104, pp. 56-63.
Southwest Indian Ridge ⓘ BC‐10 station	[Opal] Linsy, P., L. Surya Prakash, Parijat Roy, Muhammad Shuhail, and P. John Kurian. (2023) "Geochemical Characteristics of Iron in a Sediment Core at 63°40′ E, Eastern Southwest Indian Ridge: Implications on Regional Hydrothermal Activities and Source Origin" Minerals 13, no. 2: 209. https://doi.org/10.3390/min13020209
ⓘ Longqi vent field	[Opal] Wang, Y., Wu, Z., Sun, X., Deng, X., Guan, Y., Xu, L., ... & Cao, K. (2018). He–Ar–S Isotopic Compositions of Polymetallic Sulphides from Hydrothermal Vent Fields along the Ultraslow-Spreading Southwest Indian Ridge and Their Geological Implications. Minerals, 8(11), 512.

Indonesia
Bali Province ⓘ Mount Batur	[Opal-A var: Opal-AN] Rod Martin personal collection
Banten Province Lebak Regency ⓘ Cilayang village (Kali Maya)	[Opal] Extra Lapis - English No. 10 Opal; Sun, T. T., Mok, P. C., Paul, S. L., Paramita, M., Arps, C. E., Atichat, W., ... & Wijaya, K. (2008). Precious Opal from Java (Gemmological properties, micro-and nano-structures) Date: 10-05-2008.
Curugbitung Sub-District ⓘ Ciburuy Village	[Opal] Collection of Alex Earl, and obtained from local miners
Bengkulu Province Rejang Lebong District (Rediang Lebong District) ⓘ Tambang Sawah	[Opal] Canadian Mineralogist Vol. 16, pp. 651-657 (1978)
Central Sulawesi Province Talau ⓘ Poboya Gold Mine	[Opal] Syafrizal, Tomy Alvin Rivai, Kotaro Yonezu, Damar Kusumanto, Koichiro Watanabe, and Arie Naftali Hawu Hede. (2017) "Characteristics of a Low-Sulfidation Epithermal Deposit in the River Reef Zone and the Watuputih Hill, the Poboya Gold Prospect, Central Sulawesi, Indonesia: Host Rocks and Hydrothermal Alteration" Minerals 7, no. 7: 124. https://doi.org/10.3390/min7070124
East Java Province Banyuwangi Regency ⓘ Kawah Ijen (Ijen volcano)	[Opal] Lowenstern, J. B., van Hinsberg, V., Berlo, K., Liesegang, M., Iacovino, K., Bindeman, I. N., & Wright, H. M. (2018). Opal-A in glassy pumice, acid alteration, and the 1817 phreatomagmatic eruption at Kawah Ijen (Java), Indonesia. Frontiers in Earth Science, 6, 11.
ⓘ Java	[Opal] Sujatmiko, Dr H. C. Einfalt, Dr U. Henn (2007) Opal from Java, Indonesia and Its Varieties. http://www.hagi.or.id/paper/opal-from-java-indonesia-and-its-varieties/
ⓘ Lampung Province	[Amber] Richard Gunter Collection
Papua Province Mimika Regency Gunung Bijih District (Grasberg District) ⓘ West Grasberg Resource	[Opal] Prendergast, K. (2003). Porphyry-related hydrothermal systems in the Estberg District, Papua, Indonesia (Doctoral dissertation, James Cook University).
West Java Province Garut Regency ⓘ Papandayan volcano	[Opal] Mazot, A., Bernard, A., Sutawidjaja, I.S. (2007) Hydrothermal system of the Papandayan Volcano, West Java, Indonesia and its geochemistry evolution of thermal water after the November 2002 eruption. Jurnal Geologi Indonesia, 2:1, 15-29.

Iran
Tehran Province ⓘ Kuh-e-Aradeh	[Opal] Bazargani-Guilani, K., & Rabbani, M. S. (2004). Amygdaloidal and other cavity filling zeolites of Kuh-e-Aradeh, Central Iran. Journal of Sciences, Islamic Republic of Iran, 15(2), 149-157.

Israel
Haifa District Hof HaCarmel ⓘ Kebara Cave	[Opal] Weiner, S., Goldberg, P., & Bar-Yosef, O. (1993). Bone preservation in Kebara Cave, Israel using on-site Fourier transform infrared spectrometry. Journal of Archaeological Science, 20(6), 613-627.
ⓘ Naftali Mountains	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
Northern District (HaZafon District) Central Jordan Valley Beit She'an ⓘ Menahemiya (Menahamiya)	[Opal]
Golan Heights ⓘ Mt Hermon	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
ⓘ Kiryat Shmona (Qiryat Shemona)	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
Northern Jordan Valley ⓘ Lake Huleh Preserve	[Opal] Cowgill, U.M. (1989): A naturally occurring alpha magnesium oxalate dihydrate from the northern Jordan Valley (Israel). Mineralogical Magazine: 53: 505-507
Southern District (HaDarom District) ⓘ Arad	[Opal] Allan W. Eckert (1997) The World of Opals
ⓘ Barboor	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
Dead Sea ⓘ Har Ye'elim	[Opal] Kruszewski, Ł., Palchik, V., Vapnik, Y., Nowak, K., Banasik, K., & Galuskina, I. (2021). Mineralogical, Geochemical, and Rock Mechanic Characteristics of Zeolite-Bearing Rocks of the Hatrurim Basin, Israel. Minerals, 11(10), 1062.
ⓘ Kokhav	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
Tamar Regional Council ⓘ Arad Mine	[Opal] www.mineralmundi.com; Tonsuaadu, K., Veiderma, M., Koel, M., & Nathan, Y. (2000). Thermal analysis of Israeli phosphorites. In PROCEEDINGS-ESTONIAN ACADEMY OF SCIENCES CHEMISTRY (Vol. 49, No. 1, pp. 44-52). TRUEKITUD OU.
Hatrurim Basin Gurim anticline ⓘ Clastic dikes	[Opal] Sokol, E. V., Gaskova, O. L., Kozmenko, O. A., Kokh, S. N., Vapnik, E. A., Novikova, S. A., & Nigmatulina, E. N. (2014, November). Clastic dikes of the Hatrurim basin (western flank of the Dead Sea) as natural analogues of alkaline concretes: Mineralogy, solution chemistry, and durability. In Doklady Earth Sciences (Vol. 459, No. 1, pp. 1436-1441). Pleiades Publishing.
ⓘ Scorpions Pass	[Opal]

Italy
Basilicata Potenza Province Melfi ⓘ Vallone Toppo di Lupo	[Opal] "Giorgio Bortolozzi (visual identification)"
Calabria Metropolitan City of Reggio Calabria ⓘ Bivongi	[Opal-A var: Opal-AN] samples in Messina University and Ferdinando Giovine collection
ⓘ Giogli Mine	[Opal-A var: Opal-AN] Messina University collection Ferdinando Giovine collection
ⓘ Melito di Porto Salvo (Melito)	[Amber] Mantovani P. (1877): Ligniti nella provincia di Reggio Calabria. Boll. R. Com. Geol. d'Italia, 8, 376-377; Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.
Campania Naples Pozzuoli ⓘ Antiniana (Scarfoglio)	[Opal] Russo, M., Campostrini, I., Demartin, F. (2017): I minerali di origine fumarolica dei Campi Flegrei: Solfatara di Pozzuoli (Napoli) e dintorni. Micro, 15, 122-192.
ⓘ Pisciarelli di Agnano	[Opal] Russo M. (1984): La jarosite de "I Pisciarelli" (Napoli). Rivista Mineralogica Italiana, 8, 3 (3-1984), 109-110.
ⓘ Solfatara di Pozzuoli	[Opal] Pichler, H., (1970): Italienische Vulkangebiete II, Bornträger Berlin Stuttgart
ⓘ "Bocca Grande" fumarole	[Opal] Russo, M., Campostrini, I., Demartin, F. (2017) I minerali di origine fumarolica dei Campi Flegrei: Solfatara di Pozzuoli (Napoli) e dintorni. Micro: 15: 122-192.
Somma-Vesuvius Complex Boscotrecase ⓘ Boscotrecase thermal area ("Tenorite pit")	[Opal] Parascandola, A. (1959) Notizie vesuviane. Il Vesuvio dal marzo 1948 al dicembre 1958. Bollettino della Società dei Naturalisti in Napoli, 68, 184-340.
ⓘ Mount Vesuvius	[Opal] Russo, M., 2006: I minerali di formazione fumarolica della grande eruzione vesuviana del 1906; Balassone, G.; Petti, C.; Mondillo, N.; Panikorovskii, T.L.; de Gennaro, R.; Cappelletti, P.; Altomare, A.; Corriero, N.; Cangiano, M.; D’Orazio, L. (2019) Copper Minerals at Vesuvius Volcano (Southern Italy): A Mineralogical Review. Minerals 9, 730.
Torre del Greco ⓘ Vesuvius fumaroles at the crater bottom	[Opal] Russo, M., and Punzo, I. (2004) I Minerali del Somma-Vesuvio. AMI Associazione Micro-mineralogica Italiana, Tipografia Fantigrafica s.r.l., Cremona, 320 pp.; Cruciani, G., Orlandi, P., Pasero, M., and Russo, M. (2005) First Italian occurrence of cumengéite from Vesuvius: crystal-structure refinement and revision of the chemical formula. Mineralogical Magazine, 69, 6, 1037–1045.
ⓘ Vesuvius fumaroles	[Opal] Pelloux, A. (1927) The minerals of Vesuvius. American Mineralogist, 12, 14–21; Parascandola, A. (1947) Notizie vesuviane. Lo stato del Vesuvio nel 18 e 25 marzo 1947. Bollettino della Società dei Naturalisti in Napoli, 56, 12-16; Parascandola, A. (1951) I minerali del Vesuvio nella eruzione del marzo 1944 e quelli formati durante l’attuale periodo di riposo. Bollettino della Societa` Geologica Italiana, 70, 523–526; Parascandola, A. (1959) Notizie vesuviane. Il Vesuvio dal marzo 1948 al dicembre 1958. Bollettino della Società dei Naturalisti in Napoli, 68, 184-340; Russo, M., and Punzo, I. (2004) I Minerali del Somma-Vesuvio. AMI Associazione Micro-mineralogica Italiana, Tipografia Fantigrafica s.r.l., Cremona, 320 pp.; Cruciani, G., Orlandi, P., Pasero, M., and Russo, M. (2005) First Italian occurrence of cumengéite from Vesuvius: crystal-structure refinement and revision of the chemical formula. Mineralogical Magazine, 69, 6, 1037–1045; Russo, M., and Campostrini, I. (2011) Ammineite, matlockite and post 1944 eruption fumarolic minerals at Vesuvius. Plinius, 37, 312; Demartin, F., Campostrini, I., Castellano, C., and Russo, M. (2014) Parascandolaite, KMgF3, a new perovskite type fluoride from Vesuvius. Physics and Chemistry of Minerals, 41, 403–407.
Ottaviano ⓘ Vesuvius fumaroles on eastern crater rim	[Opal] Russo, M., and Campostrini, I. (2011) Ammineite, matlockite and post 1944 eruption fumarolic minerals at Vesuvius. Plinius, 37, 312; Demartin, F., Campostrini, I., Castellano, C., and Russo, M. (2014) Parascandolaite, KMgF3, a new perovskite type fluoride from Vesuvius. Physics and Chemistry of Minerals, 41, 403–407.
ⓘ Fumarole B5 ("Cotunnite pit")	[Opal] Campostrini, I., Demartin, F., Russo, M. (2019) Sbacchiite, Ca2AlF7, a new fumarolic mineral from the Vesuvius volcano, Napoli, Italy. European Journal of Mineralogy: 31: 153-158.
Emilia-Romagna Forlì-Cesena Province ⓘ Mercato Saraceno	[Amber] Bombicci, L. (1890) La collezione di Ambre Siciliane posseduta dal museo di Mineralogia della R. Università di Bologna (dono del Ministero di pubblica istruzione nel 1889) e nuove considerazioni sull’origine dell’Ambra gialla. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 4, 10 (1889-1990), 473-486; Bombicci, L. (1894) Descrizione degli esemplari di solfo nativo cristallizzato delle solfare di Romagna raccolti e classificati dall'autore nel Museo mineralogico della R. Università di Bologna. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 5, 4, 737-816; Skalski, A.W., and Viggiani, A. (1990) Fossil resin in Sicily and the northern Apennines: geology and organic content. Praze Muzeum Ziemi, 41, 37–49.
Metropolitan City of Bologna Alto Reno Terme Granaglione ⓘ Lustrola	[Opal] Milani, M., Calzolari, M., Poli, M. (2016): Ritrovamento di opale nella formazione del Macigno. Micro, 1/2016, 21-25.
Loiano (Lojano) ⓘ Scanello	[Amber] Bombicci, L. (1873) Descrizione della mineralogia generale della provincia di Bologna. Prima parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 4, 59-139; Skalski, A.W., and Viggiani, A. (1990) Fossil resin in Sicily and the northern Apennines: geology and organic content. Praze Muzeum Ziemi, 41, 37–49; Angelini, I., and Bellintani, P. (2005) Archaeological ambers from northern Italy: an FTIR-DRIFT study of provenance by comparison with the geological amber database. Archaeometry, 47, 2, 441–454; http://www.academia.edu/991620/northern_Italy_ARCHAEOLOGICAL_AMBERS_FROM_NORTHERN_ITALY_AN_FTIR_DRIFT_STUDY_OF_PROVENANCE_BY_COMPARISON_WITH_THE_GEOLOGICAL_AMBER_DATABASE
Monterenzio ⓘ San Clemente	[Amber] Bombicci, L. (1873) Descrizione della mineralogia generale della provincia di Bologna. Prima parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 4, 59-139.
Modena Province Fiorano Modenese Nirano ⓘ Nirano badlands	[Opal] http://www.mineralimodenesi.it/Schede/Nirano.htm
Prignano sulla Secchia ⓘ Castelvecchio	[Amber] Malagoli, M. (1884) Cenni sulla mineralogia generale del Modenese e del Reggiano. Atti della Società dei Naturalisti di Modena, Rendiconti delle adunanze (1884-85), serie 3, 2, 30-48; Skalski, A.W., and Viggiani, A. (1990) Fossil resin in Sicily and the northern Apennines: geology and organic content. Praze Muzeum Ziemi, 41, 37–49; Angelini, I., and Bellintani, P. (2005) Archaeological ambers from northern Italy: an FTIR-DRIFT study of provenance by comparison with the geological amber database. Archaeometry, 47, 2, 441–454; http://www.academia.edu/991620/northern_Italy_ARCHAEOLOGICAL_AMBERS_FROM_NORTHERN_ITALY_AN_FTIR_DRIFT_STUDY_OF_PROVENANCE_BY_COMPARISON_WITH_THE_GEOLOGICAL_AMBER_DATABASE; Neri, M., Roghi, G., Ragazzi, E., Fornaciari, E., Giusberti, L., and Papazzoni, C.A. (2016) Nuovi dati stratigrafici sull'ambra di Castelvecchio di Prignano (MO). In: Rook, L., Bartolini, S., and Ghezzo, E. (eds.) Paleodays 2016. La Società Paleontologica Italiana a Faenza. XVI Riunione annuale SPI (Società Paleontologica Italiana). Museo Civico di Scienze Naturali "Malmerendi", Faenza, 25-27 maggio 2016. Volume dei riassunti e guida all'escursione, page 63.
Parma Province Berceto Corchia mine ⓘ Perboni Q. 750	[Opal] ADORNI F., GUELFI F. (1997) - La miniera di Fe e Cu di Corchia, Berceto, Appennino Parmense. - Riv. Min. It., N. 3, 217-250.
ⓘ Rio Bassi Stope	[Opal] Adorni F., Guelfi F. (1997) - La miniera di Fe e Cu di Corchia, Berceto, Appennino Parmense. - Riv. Min. It. N 3, 217-250.
Medesano Sant'Andrea Bagni ⓘ Case Montanini quarry	[Opal] Adorni, F., Tateo, F., Adorni, B. (2004): La melanoflogite di Case Montanini (S. Andrea Bagni, Medesano, Appennino parmense). Rivista Mineralogica Italiana, 28, 126-136.
ⓘ Faieto quarry	[Opal] Adorni, F., Tateo, F., Adorni, B. (2004): La melanoflogite di Case Montanini (S. Andrea Bagni, Medesano, Appennino parmense). Rivista Mineralogica Italiana, 28, 126-136.
Varano de' Melegari ⓘ I Camilloni	[Amber] Adorni, F., Battilocchi, G., Bersani, D. & Calderini, V. (2010). Le septarie dell'Appennino Parmense. Rivista Mineralogica Italiana, 222-241.
Rimini Province Sant'Agata Feltria ⓘ Marazzana Mine	[Opal] Bombicci, L. (1894): Descrizione degli esemplari di solfo nativo cristallizzato delle solfare di Romagna raccolti e classificati dall'autore nel Museo mineralogico della R. Università di Bologna. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 5, 4, 737-816.
Friuli Venezia Giulia Pordenone Province Frisanco ⓘ Muiè Stream (Mujè Stream)	[Amber] Rimoli, G., and Dreon, A.L. (1998) Notizie mineralogiche dell’area del pordenonese con particolare riguardo ai minerali della Val Cellina e della Val Colvera. Bollettino Società Naturalisti “Silvia Zenari”, 22, 45-62; Ragazzi, E., Avanzini, M., Dieni, I., Roghi, G., and Stefani, C. (2012) New amber findings in Northeastern Italy: suggestions for an integrated view on fossil resin raison d’être. In: Bianchi, V., Gattolin, G., and Rigo, M. (eds.), Note brevi e riassunti. X Congresso GEOSED “Associazione Italiana per la Geologia del sedimentario”, Feltre, 2-6 Luglio 2012. Rendiconti Online della Società Geologica Italiana, 20, 71-75; Trevisani, E., and Ragazzi, E. (2013) L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Udine Province ⓘ Comeglians	[Opal] "Giorgio Bortolozzi (visual identification)"; Bortolozzi, G.M., Bracco, R., De Tuoni, F., Vidus, L., Bittarello, E., Marengo, A., Ciriotti, M.E., Zorzi, F. (2018) Antiche miniere e affioramenti metalliferi a Comeglians (Val Degano, Friuli-Venezia Giulia): recenti ritrovamenti. Micro, 16, 1-2018, 2-36.
ⓘ Dogna	[Amber] - Roghi G., Gianolla P., Ragazzi E. (2002): Paleobotanical features of Upper Triassic amber in the Southern Alps (Italy). Abstract, 6th European Paleobotany-Palynology Conference, Athens, unpaged. - Preto N., Roghi G., Gianolla P. (2005): Carnian stratigraphy of the Dogna area (Julian Alps, northern Italy): tessera of a complex palaeogeography. Boll. Soc. Geol. Ital., 124, 269-279. - Roghi G., Ragazzi E., Gianolla P. (2006): Triassic Amber of the Southern Alps (Italy). Palaios, 21, 143-154.
San Pietro al Natisone Vernasso ⓘ Vernasso Quarry	[Amber] - Roghi G., Ragazzi E., Fedele P. (2004): L’ambra Cretacea delle Dolomiti e delle Prealpi Giulie. Giornate di Paleontologia 2004, Bolzano, 21-23 Maggio, Abstracts Book, 52. - Trevisani E. (ed.) (2007): Ambra. Il fascino di una gemma tra mito, scienza e vanità. Minerva Edizioni, Bologna, 128 pp. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Lazio Latina Province Ponza Ponza Island ⓘ Cala Fontana old quarry	[Opal] E. Passaglia et al. , Eur. Journ. Mineral. , 1995, 7, pp. 429-438.
Metropolitan City of Rome Capital ⓘ Alban Hills	[Opal] Federico M., Gianfagna A. - Al, Ca and Fe3+ bearing opal pseudomorph after melilite in ejecta and lavas of the Alban Hills, Italy. pp. 149-157
Allumiere ⓘ Allumiere Quarries	[Opal] Negretti,G.C.;Lombardi,G.;Morbidelli,L.:”Studio geopetrografico del complesso vulcanico tolfetano-cerite (Lazio).IV:Le manifestazioni vulcaniche acide del settore civitavecchiese tolfetano”,Quad.CNR,4,1-173 (1966).
ⓘ Caldano creek	[Opal] I minerali del Museo Archeominerario "Klitsche de la Grange"Allumiere,Provincia di Roma.(2000)
ⓘ Monte Rovello	[Opal-A var: Opal-AN] Napoleoni, C., Della Ventura, G., Conte, A., Lucci, F. and Di Domenico, D. (2021) Opale e silice microcristallina nei Monti della Tolfa-Allumiere. Il Cercapietre, 3-21.
ⓘ Sasso della Strega	[Opal-A var: Opal-AN] Napoleoni, C., Della Ventura, G., Conte, A., Lucci, F. and Di Domenico, D. (2021) Opale e silice microcristallina nei Monti della Tolfa-Allumiere. Il Cercapietre, 3-21.
ⓘ Ariccia	[Opal] De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol
Campagnano di Roma ⓘ Monte Cavalluccio	[Opal] Eur. J. Mineral. , 1993, 5, pp. 53-58.
Monte Compatri Laghetto (Laghetto di Montecompatri) ⓘ Laghetto quarries ?	[Opal] Carlini, R., and Signoretti, E. (2018) Il Lazio classico: le cave di leucitite della provincia di Roma (Vallerano, Laghetto e Osa). Fossils & Minerals, 4, 24-53.
Rome Osteria dell'Osa ⓘ Osa Quarry ?	[Opal] Carlini, R., and Signoretti, E. (2018) Il Lazio classico: le cave di leucitite della provincia di Roma (Vallerano, Laghetto e Osa). Fossils & Minerals, 4, 24-53.
Valleranello ⓘ Vallerano Quarries	[Opal] "Giorgio Bortolozzi (visual identification)"; Carlini, R., and Signoretti, E. (2018) Il Lazio classico: le cave di leucitite della provincia di Roma (Vallerano, Laghetto e Osa). Fossils & Minerals, 4, 24-53.
Viterbo Province Capranica ⓘ Campo Padella	[Opal] "Giorgio Bortolozzi (visual identification)"
ⓘ Cassia Road km 61.5	[Opal] "Giorgio Bortolozzi (visual identification)"
ⓘ Ischia di Castro	[Opal] Di Domenico Dario
Montalto di Castro Pietra Massa Locality ⓘ Campomorto Quarry	[Opal-A var: Opal-AN] Passaglia, E. & Turconi, B. (1982): Silicati ed altri minerali di Montalto di Castro - VT. Rivista Mineralogica Italiana, 4/1982, 97-110.
Onano ⓘ Montenero Quarry	[Opal] "Giorgio Bortolozzi (visual identification)"
Liguria Genoa Genoa Borzoli ⓘ Mt. Ramazzo Mine	[Opal] Giuseppe Pipino - L'antica miniera di Monte Ramazzo e i suoi minerali - Rivista Mineralogica Italiana, Milano, vol. 8, fasc. 3, 1977
ⓘ Varenna Valley	[Opal] Antofilli, Borgo, Palenzona, 1985. I nostri minerali. Geologia e mineralogia in Liguria. Edizioni Melita, La Spezia.
Masone ⓘ I Piani	[Opal] Antofilli, Borgo, Palenzona, 1985. I nostri minerali. Geologia e mineralogia in Liguria. Edizioni Melita, La Spezia.
Ne ⓘ Cassagna Mine	[Opal] "Giorgio Bortolozzi (visual identification)"
ⓘ Molinello Mine	[Opal] Marchesini, M., Pagano, R. (2001) The Val Graveglia manganese district, Liguria, Italy. The Mineralogical Record: 32: 349-379; 415.
ⓘ Nascio	[Opal] "Giorgio Bortolozzi (visual identification)"
Reppia ⓘ Gambatesa Mine	[Opal] Redazione (2005): Sistematica ligure: resoconto 2005. Notiziario di Mineralogia Ferrania Club, 19, 3-5.
Tiglieto Olbicella ⓘ Rio Pian del Foco	[Opal] Cortesogno L., Lucchetti G., Penco A.M. - 1975 - Associazioni a zeoliti nel "Gruppo di Voltri" : caratteristiche mineralogiche e loro significato - rend. S.I.M.P. - Milano, vol. 31, n.2 pp. 673-710
Imperia Province Ventimiglia ⓘ Monte Bellenda	[Amber] Issel A. (1892): Liguria geologica e preistorica. A. Donath Editore, Genova, Vol. 1, 440 pp.; Antofilli M., Borgo E., Palenzona A. (1985): I nostri minerali. Geologia e mineralogia in Liguria. II Edizione. SAGEP Editrice, Genova, 296 pp.
La Spezia Province Rocchetta di Vara ⓘ Monte Nero Mine	[Opal] probed by Balestra C.
Savona Province Sassello ⓘ Veirera	[Opal] Antofilli, M., Borgo, E., Palenzona, A. (1985): I nostri minerali. Geologia e mineralogia in Liguria. II Edizione. SAGEP Editrice, Genova, 296 pp.
Lombardy Bergamo Province ⓘ San Martino Valley	[Opal] Maida, F. (2002): Descrizione delle specie e varietà di minerali e loro ritrovamento nella Bergamasca. G.O.M. Gruppo Orobico Minerali - Novecento Grafico, Ed., Bergamo 82 pp. (geologic part by F. Pezzotta).
Pavia Province ⓘ Cigognola	[Opal] Barelli, V. (1835) Cenni di statistica mineralogica degli Stati di S.M. il Re di Sardegna, ovvero Catalogo ragionato della raccolta formatasi presso l'Azienda Generale dell'Interno. Tipografia Giuseppe Fodratti, Torino, 686 pp.; Jervis, G. (1874) I tesori sotterranei dell'Italia. Vol. 2: Regione dell’Appennino e vulcani attivi e spenti dipendentivi. Ermanno Loescher, Torino, XVIII+624 pp.
Ponte Nizza ⓘ Pizzocorno	[Opal] Barelli, V. (1835) Cenni di statistica mineralogica degli Stati di S.M. il Re di Sardegna, ovvero Catalogo ragionato della raccolta formatasi presso l'Azienda Generale dell'Interno. Tipografia Giuseppe Fodratti, Torino, 686 pp.; Jervis, G. (1874) I tesori sotterranei dell'Italia. Vol. 2: Regione dell’Appennino e vulcani attivi e spenti dipendentivi. Ermanno Loescher, Torino, XVIII+624 pp.
Sondrio Province Chiavenna ⓘ Tanno	[Opal] Bedognè, F. (1991) I minerali dei differenziati acidi di Tanno (Val Chiavenna). Il Naturalista Valtellinese - Atti Mus. civ. Stor. nat. Morbegno, 2, 35-45.
Chiesa in Valmalenco ⓘ Sissone Valley	[Opal]
Grosio Grosina Valley ⓘ Stavalina	[Opal-A var: Opal-AN] Tabacchi C. (1974) - Pegmatiti della Val Grosina (Sondrio) in - Notizie del Gruppo Min. Lombardo, Milano, fasc.4, Dec. 1974 pp. 85-86 ; Bedognè, F., Montrasio, A., Sciesa, E. (2006) I minerali della media-alta Valtellina, delle Orobie valtellinesi e della Val Poschiavo. Aggiornamenti sulle altre località della provincia di Sondrio. Bettini, Sondrio, 255 pp.
Novate Mezzola ⓘ Munt Valley Quarries	[Opal] Ghizzoni, S. & Mazzoleni, G. (2005): Itinerari mineralogici in val Codera. Geologia Insubrica, Ed., Milano, 316 pp.
Valdisotto ⓘ Cepina	[Opal] Romani, E., and Mottana, A. (1997) I dopo Pola 1987-1997. Minerali e rocce dell'Alta Valtellina nella raccolta del Museo Mineralogico Naturalistico di Bormio. Tipografia Compagnoni, Valdidentro, 115 pp.; Bedognè, F., Montrasio, A., and Sciesa, E. (2006) I minerali della media-alta Valtellina, delle Orobie valtellinesi e della Val Poschiavo. Aggiornamenti sulle altre località della provincia di Sondrio. Bettini, Sondrio, 255 pages.
Varese Province ⓘ Cuasso al Monte	[Opal] Boscardin M., De Michele V. and Scaini G. (1972): Itinerari mineralogici della Lombardia. Museo Civico di Storia Naturale, Milano 1972, pagg. 124.; Pezzotta, F., Diella, V., Guastoni, A. (1999): Chemical and paragenetic data on gadolinite-group minerals from Baveno and Cuasso al Monte, Southern Alps: mineralogy and inferences. American Mineralogist, 84(5-6), 782-789.
Cavagnano ⓘ Laghetto Quarry	[Opal] capponi Fulvio Piero collection. Collected since 03.24.2018
Cuasso al Piano ⓘ Bonomi Quarry	[Opal] Grill, E., Fagnani, G. (1943): Itinerari mineralogici. Comune di Cuasso al Monte. Natura, 34, 2, 63-69; Boscardin, M., De Michele, V., Scaini, G. (1970): Itinerari mineralogici della Lombardia. Natura, 61,1, 5-120; (as a monograph) 1972, Ed. Museo Civ. St. Nat. e Soc. It. Sci. Nat., Milano, 124 pp.
ⓘ Gebel Quarry (Mantegazza Quarry; Subalpina Quarry; Bianchi Quarry)	[Opal] Grill, E., Fagnani, G. (1943): Itinerari mineralogici. Comune di Cuasso al Monte. Natura, 34, 2, 63-69; Boscardin, M., De Michele, V., Scaini, G. (1970): Itinerari mineralogici della Lombardia. Natura, 61,1, 5-120; (as a monograph) 1972, Ed. Museo Civ. St. Nat. e Soc. It. Sci. Nat., Milano, 124 pp.
ⓘ Puricelli Quarry	[Opal-A var: Opal-AN] Fabio Brignoli collection
Marche Ancona Province Genga ⓘ Frasassi Caves (Grotte di Frasassi; Fiume-Vento karst system; Grotta del Fiume-Grotta Grande del Vento karst complex; Grotta Grande del Vento)	[Opal] Bertolani, M., Garuti, G., Rossi, A., Bertolani Marchetti, M. (1976) Motivi di interesse mineralogico e petrografico nel complesso carsico Grotta Grande del Vento-Grotta del Fiume. Le Grotte d’Italia, 4, 4, 109-144; D'Angeli, I. M., Carbone, C., Nagostinis, M., Parise, M., Vattano, M., Madonia, G., and De Waele, J. (2018) New insights on secondary minerals from Italian sulfuric acid caves. International Journal of Speleology, 47, 3, 271-291.
Macerata Province ⓘ Poggio San Vicino	[Opal] Del Caldo, A., Moro, C., Gramaccioli, C.M., Boscardin, M. (1973): Guida ai minerali. Fratelli Fabbri Editori, Milano, 208 pp.; Cingolani G. (1979) Antica ricerca di manganese di Monte San Vicino (Mc) - Rivista Mineralogica Italiana fasc. 3 pag. 84
Piedmont Biella Province Campiglia Cervo ⓘ Quittengo	[Opal] Piccoli, G. C., Maletto, G., Bosio, P., & Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo F. Eusebio - Alba, 607 pag.
San Paolo Cervo ⓘ Colombari quarry	[Opal] Martini, B., Salvetti, A., Dalla Fontana, G., Boscardin, M., Rocchetti, I., Ciriotti, M.E., Taronna, M., Ambrino, P. (2012). I minerali delle cave di sienite Colombari e Vej della Balma Valle Cervo (Biella, Piemonte). Micro, 10, 110-135.
ⓘ Vej della Balma	[Opal] Martini, B., Salvetti, A., Dalla Fontana, G., Boscardin, M., Rocchetti, I., Ciriotti, M.E., Taronna, M., Ambrino, P. (2012). I minerali delle cave di sienite Colombari e Vej della Balma Valle Cervo (Biella, Piemonte). Micro, 10, 110-135.
ⓘ Cervo Valley	[Opal] De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol.
Cuneo Province Bagnolo Piemonte ⓘ Montoso Quarries	[Opal] Bruno Marello find & collection
ⓘ Pravallino Quarry	[Opal] Bruno Marello find & collection
Bellino ⓘ Maniglia Mt. Mine	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.; Piccoli, G.C., Vanini, F., Ciriotti, M.E., Marengo, A., Bittarello, E., Cámara, F., Kolitsch, U., Bracco, R., Balestra, C., Odicino, G., Brizio, P. (2020): Eggletonite e tamaite del Monte Maniglia, Bellino, Cuneo, Piemonte con aggiornamento sulla mineralogia locale. Micro, 18, 60-66.
Canosio Vallone della Valletta ⓘ Valletta Mine	[Opal] Cámara, F., Bittarello, E., Ciriotti, M.E., Nestola, F., Radica, F., Massimi, F., Balestra, C., Bracco, R. (2017a) As-bearing new mineral species from Valletta mine, Maira Valley, Piedmont, Italy: III. Canosioite, Ba2Fe3+(AsO4)2(OH), description and crystal structure. Mineralogical Magazine, 81, 305–317.
Metropolitan City of Turin Balangero ⓘ Poggio San Vittore asbestos mine	[Opal] Prete, R. (1995): L'amiantifera di S. Vittore, Balangero, Torino. Rivista Mineralogica Italiana, 4/1995, 313-333.
Baldissero Canavese Bettolino ⓘ Monti Pelati Nature Park	[Opal] Gramaccioli, C.M. (1975) Minerali alpini e prealpini. Istituto Italiano Edizioni Atlas, Bergamo, 2 vol., 472 pp.; Marinai & Scaini,1978. I minerali d'Italia, Rizzoli Editore,Milano
Bussoleno Tignai ⓘ Tignai Quarry	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): MInerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
Caselette ⓘ Calvo Mt. magnesite quarries (Caselette magnesite quarries)	[Opal] Jervis, G. (1873): I tesori sotterranei dell'Italia. Vol. 1: Regioni delle Alpi. Ed. Loescher, Torino, 410 pp.; Piolti, G. (1897): Sull'origine della magnesite di Caselette (Val di Susa). Mem. R. Acc. Sci. Torino, 2, 47, 126-142; Sanero, E. (1932): Sopra alcune rocce del M. Musinè (Valle di Susa). Per. Mineral., 3, 87-123; Fenoglio, M., Sanero, E., (1941): I giacimenti di magnesite delle Prealpi Piemontesi. Per. Mineral., 12, 83-111; Fenoglio, M., Sanero, E., (1942-43): Sulla presenza e diffusione della cristobalite-beta negli opali dei giacimenti di magnesite delle Prealpi Piemontesi. Atti R. Acc. Sci. Torino, 78, 265-273; Bortolami, G., Dal Piaz G.V. (1968): I filoni di gabbri rodingitici di Givoletto e Caselette nel Massiccio ultrabasico di Lanzo (Torino). Boll. Soc. Geol. It., 87, 479-490; Natale, P. (1972) : Nuove osservazioni sull’origine dei giacimenti di magnesite delle Alpi Occidentali. Boll. Ass. Min. Sub., 9, 1-2, 107-124; Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo), 607 pp.
ⓘ Sant'Abaco	[Opal] Sanero, E. (1932) Sopra alcune rocce del M. Musinè (Valle di Susa). Periodico di Mineralogia, 3, 87-123.
Cesana Torinese ⓘ Monte Cruzore (Monte Cruzeau)	[Opal] Parona, C.F. (1892) Sugli schisti silicei a radiolarie di Cesana, presso il Monginevra. Atti della Reale Accademia delle Scienze di Torino, 27, 197-211; https://digilander.libero.it/mineralweb/susa4.htm
Condove ⓘ Civrari Mountain	[Opal] Alessandro Cantamessa find & collection
Givoletto Mt. Baron ⓘ Baron d’la Seil magnesite quarry	[Opal] Fenoglio, M., Sanero, E., (1941): I giacimenti di magnesite delle Prealpi Piemontesi. Per. Mineral., 12, 83-111.
Luserna San Giovanni ⓘ Seccarezze Quarries	[Opal] Collection Giuseppe Finello
ⓘ Luserna Stone Quarries	[Opal] Ambrino, P., Brizio, P., Ciriotti, M.E., Finello, G., Marello, B. (2009). Minerali della pietra di Luserna. AMI. CD-ROM (in italian and in english)
Mezzenile Pugnetto ⓘ Borna di Pugnetto (Grotta di Pugnetto)	[Opal] Curlo, G. (1929) Sopra alcune concrezioni stalattitiformi silicee della Grotta di Pugnetto (Valle di Lanzo). Annali del Museo Civico di Storia Naturale di Genova, 53 (1928-1930), 461-464.
ⓘ Musinè Mountain	[Opal] Jervis, G. (1873): I tesori sotterranei dell'Italia. Vol. 1: Regioni delle Alpi. Ed. Loescher, Torino, 410 pp.; Piolti, G. (1897): Sull'origine della magnesite di Caselette (Val di Susa). Mem. R. Acc. Sci. Torino, 2, 47, 126-142; Sanero, E. (1932): Sopra alcune rocce del M. Musinè (Valle di Susa). Per. Mineral., 3, 87-123; Fenoglio, M., Sanero, E., (1941): I giacimenti di magnesite delle Prealpi Piemontesi. Per. Mineral., 12, 83-111; Fenoglio, M., Sanero, E., (1942-43): Sulla presenza e diffusione della cristobalite-beta negli opali dei giacimenti di magnesite delle Prealpi Piemontesi. Atti R. Acc. Sci. Torino, 78, 265-273; Bortolami, G., Dal Piaz G.V. (1968): I filoni di gabbri rodingitici di Givoletto e Caselette nel Massiccio ultrabasico di Lanzo (Torino). Boll. Soc. Geol. It., 87, 479-490; Natale, P. (1972) : Nuove osservazioni sull’origine dei giacimenti di magnesite delle Alpi Occidentali. Boll. Ass. Min. Sub., 9, 1-2, 107-124; Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): Minerali del Piemonte e della Valle d'Aosta. Amici del Museo "F. Eusebio" di Alba, Ed., Alba, 607 pp.
Oulx ⓘ "Bardonecchia road" quartzite vein	[Opal] Colomba (1900) Ricerche microscopiche e chimiche su alcune quarziti nei dintorni di Oulx (alta valle della Dora Riparia) e su alcune roccie associate. Bollettino della Società Geologica Italiana, 19, 1, 111-131; Barresi, A. (1999) La Val di Susa e i suoi minerali. Volume II. Gruppo Mineralogico e Paleontologico C.A.I.-U.G.E.T., Torino, 32 pp.; Colomba (1900) Ricerche microscopiche e chimiche su alcune quarziti nei dintorni di Oulx (alta valle della Dora Riparia) e su alcune roccie associate. Bollettino della Società Geologica Italiana, 19, 1, 111-131.
ⓘ Piossasco	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
ⓘ San Valeriano quarry	[Opal] Gennaro, V. (1931) I minerali delle serpentine di Piossasco (Piemonte). Atti della Reale Accademia delle Scienze di Torino, 66, 433-458; Piccoli, G.C., Maletto, G., Bosio, P., and Lombardo, B. (2007) Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" di Alba, L'Artigiana Srl - Azienda Grafica, Alba (Cuneo), 607 pages.
Viù ⓘ Fubina	[Opal] Airaudi, D., Ambrino, P., Ciriotti, M.E., Blass, G. (2009). Baddelleyite in cristalli dalla rodingite del Malpass, Val di Viù, Piemonte. Micro (UK report), 2/2009, 100-111
Novara Province Pella ⓘ Alzo	[Opal-A var: Opal-AN] Mariani P., Scaini G.: "I minerali d'Italia" - Rizzoli, 1978 - and A. Del Caldo, C. Del Moro, C.M. Gramaccioli, M. Boscardin M. "Guida ai Minerali" Fabbri ed. Milano, 1981
Verbano-Cusio-Ossola Province Baveno Oltrefiume Mount Camoscio ⓘ Seula mine	[Opal-A var: Opal-AN] Albertini, C. (1983) Famous mineral localities: Baveno, Italy. The Mineralogical Record, 14(3), 157-168.
Craveggia ⓘ Eglio	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
Rio Vasca ⓘ Piano del Lavonchio (Piano dei Lavonchi)	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007): Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
Crodo ⓘ Crodo gneiss quarries	[Opal] Mattioli V. (1979): Minerali Ossolani. Ed. Arti Grafiche Medesi, Milano, 268 pp.; Piccoli G.C., Maletto G., Bosio P., Lombardo B. (2007): Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" di Alba, Ed., Alba, 607 pp.
ⓘ Rencio quarries	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
Malesco ⓘ Val Loana serpentinite	[Opal] Boscardin, M., Mattioli, V., and Rocchetti, I. (2013) Minerali della Valle Vigezzo. Litotipografia Alcione, Lavis (Trento), 229 pp.
Mergozzo ⓘ Mont'Orfano (Montorfano)	[Opal] Roggiani A.G. (1969): Opale jalite e scheelite nel granito bianco del Montorfano. Rend. Soc. Ital. Mineral. Petr., 25, 2, 549-552; Boscardin M. (1972): Informazioni di mineralogia italiana. 21) Opale jalite e scheelite del Montorfano. Notizie Gruppo Mineral. Lombardo, 3, 1 (marzo 1972), 8. ; De Michele V. (1974): Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol., 408 pp.
Nibbio ⓘ Nibbio-Val Faera (Nibbio-Val Fredda) pegmatites	[Opal] Mattioli V. (1979): Lo zircone. Riv. Mineral. Ital., 3, 3 (3/2003), 74-77; Mattioli V. (1979): Minerali Ossolani. Ed. Arti Grafiche Medesi, Milano, 268 pp.
Montescheno ⓘ I Mondei (Ca' Mondei)	[Opal] Rivista Mineralogica Italiana, 23 (1), 42-49
Omegna Brughiere ⓘ Rio Inferno quarry	[Opal] Albertini, C. (2000): Ritrovamenti nel Rio Inferno, Brughiere di Omegna. Prima segnalazione nel granito di Baveno : uranofane-beta. Rivista Mineralogica Italiana, Milano: 24(2): 88-92.
Premia Premia gneiss quarries ⓘ Cadarese Quarries	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
ⓘ Passo Quarries	[Opal] Piccoli, G.C., Maletto, G., Bosio, P., Lombardo, B. (2007). Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" Alba, Ed., Alba (Cuneo) 607 pp.
ⓘ Verampio-Crego area	[Opal-A var: Opal-AN] De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol.
Trontano Cosasca ⓘ Grignaschi Quarry	[Opal-A var: Opal-AN] De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol.
ⓘ Rio Graia	[Opal] Mattioli, V. (1976): Località mineralogiche consigliate: Rio Graja, Trontano, Valle Vigezzo. Notiziario del Gruppo Mineralogico Lombardo, 2/1976, 40-42
Sardinia Metropolitan City of Cagliari Capoterra ⓘ Arcu su Linnarbu	[Opal] Olmi F., Sabelli C., Senesi F., Stara P., 2002. La mineralizzazione uranifera di Arcu su Linnarbu. Riv. Miner. Ital., 3: 148-169.
Nuoro Province ⓘ Macomer	[Opal] Vasco Trancoso Collection
Oristano Province ⓘ Masullas	[Opal] - Conti-Vecchi, G. & Stara, P.(1991): Minerali della Sardegna, Della Torre Edizioni, Cagliari, 276 pp.
ⓘ Conca Cannas quarry ("Fradelloni quarry")	[Opal] "Giorgio Bortolozzi (visual identification)"
ⓘ Montresta	[Opal] Giorgio Bortolozzi visual identification
Sassari Province ⓘ Aggius	[Opal] Gamboni, A. & Gamboni, T. (2006) - Gallura, Tesori nel Granito (i minerali delle pegmatiti granitiche) - J. Webber Ed,Sassari,190pp.
ⓘ Anglona	[Opal] Ghiara M.R., Petti C., Franco E., Lonis R., Luxoro S., Gnazzo L. (1999): Occurrence of clinoptilolite and mordenite in Tertiary calc-alkaline pyroclastites from Sardinia (Italy). Clays and Clay Minerals, 47, 3, 319-328.
Arzachena Mt. Mazzolu ⓘ Lu Patenti Quarry	[Opal] Gamboni, A., Cuccuru, S., Casini, L. & Marini, A. (2012) I minerali del Monte Mazzolu, Cava Lu Patenti, Arzachena (OT), Sardegna. Rivista Mineralogica Italiana: 3/2012: 144-157.
ⓘ Mt. Mazzolu Quarry	[Opal] S. Cuccuru, A. Gamboni & L. Casini (2011): The Mt. Mazzolu quarry: a new mineralogical locality. PLINIUS 37, 304.
Calangianus ⓘ Furru e Conca Quarries	[Opal] Gamboni, A., Gamboni, T., Pileri, P. (1997) Su alcuni minerali del massiccio granitico del monte Limbara zona "Furru e Conca", comune di Calangianus. Rivista Mineralogica Italiana: 2/1997: 123-134.
La Maddalena ⓘ Caprera Island	[Opal] Gamboni, A., Gamboni, T., Bucci, A. (1996): Ritrovamento di Bertrandite all’isola di Caprera, Arcipelago di La Maddalena. Rivista Mineralogica Italiana, 3/1996, 278-279
La Maddalena Island ⓘ Cala Francese Quarries	[Opal] Billows, E. (1941): I minerali della Sardegna ed i loro giacimenti. Sardegna Mineraria, Istituto per gli studi Sardi, Regia Università di Cagliari.
ⓘ Spargi Island	[Opal] • Gamboni, A., Gamboni, T., Nonnis, O. (1997): I minerali dell'arcipelago di La Maddalena. Paolo Sorba, Ed., La Maddalena, 100 pp. ; Gamboni, A., Cuccuru, S., Gamboni, T. & Bargone, J. (2013). I minerali dell'isola di Spargi. Arcipelago di La Maddalena, Sardegna Nord Orientale. Rivista Mineralogica Italiana, 2/2013, 116-128.
ⓘ Nulvi	[Opal] "Giorgio Bortolozzi (visual identification)"
Ozieri ⓘ Su Elzu	[Opal] "Giorgio Bortolozzi (visual identification)"
Palau ⓘ Mt. Canu Quarries	[Opal] Gamboni A., Gentile P., Mascia S., De Vito A., Gamboni T., 2004. Monte Canu: uranofane-beta e altri minerali delle pegmatiti granitiche. Riv. Miner. Ital., 3: 138-145
ⓘ Ploaghe	[Opal-A var: Opal-AN] Antonio Gamboni Collection
ⓘ Badde ia/Mt. Perucci-Selvani quarries	[Opal] Conti-Vecchi, G. & Stara, P. (1991) - Minerali della Sardegna - Della Torre Ed,276pp.
ⓘ Funtanedda Ulumu Quarry	[Opal] Gamboni, A., Cuccuru, S. & Carta, M. (2015) - I minerali della cava Funtanedda Ulumu, Ploaghe, Provincia di Sassari, Sardegna - Rivista Mineralogica Italiana, 1/2015,16-29.
Sant'Antonio di Gallura ⓘ Priatu Quarries	[Opal] Gamboni, A., Gamboni, T. (1998) - Babingtonite e "Granati" delle pegmatiti granitiche della Gallura, Sardegna nord-orientale. Rivista Mineralogica Italiana, 4, Milano.
Telti ⓘ San Bachisio Quarries	[Opal] Gamboni, A., Gelosa, M., Gamboni, T. (2001): Ortoclasio ed altri minerali delle pegmatiti di S. Bachisio, Telti, Gallura, Sardegna N.E. Rivista Mineralogica Italiana, 1/2001, 30-40
Tempio Pausania Giogantinu and Balistreri Peaks ⓘ Mount Limbara	[Opal] Gamboni, A., Gamboni, T. (2006): Gallura, tesori nel granito, i minerali delle pegmatiti granitiche. Webber Editore, Sassari, 190 pp.
South Sardinia Province Domusnovas ⓘ Sa Duchessa Mine	[Opal] "Giorgio Bortolozzi (visual identification)"
Gonnesa ⓘ Punta della Torre Mine	[Opal] Stara, P., Rizzo, R., and Tanca, G.A. [with contributions of Vinci, A., and Astolfi, M.] (1996) Iglesiente e Arburese. Miniere e Minerali. Associazione Mineralogica Sarda, Associazione Mineralogica Domusnovas, Gruppo Mineralogico Arburese, Gruppo Mineralogico Paleontologico Piacentino, Gruppo Mineralogico Lombardo et al. Ed., Siena, Vol. 1, 239 pp.
ⓘ Orroli	[Opal-A var: Opal-AN] Conti-Vecchi G. Stara P. (1991) - Minerali della Sardegna - Edizioni Della Torre - Cagliari 276 pp
San Vito ⓘ Bruncu Sciolas skarnoid outcrops	[Opal] Stara, P., Rizzo, R., Brizzi, G. (1993) Sarrabus. Miniere e Minerali. Associazione Mineralogica Sarda, Gruppo Mineralogico Lombardo, Associazione Piemontese Mineralogia Paleontologia e Mostra Torinese Minerali, Centro Mineralogico Varesino, Amici Mineralogisti Fiorentini, Gruppo Mineralogico Paleontologico Piacentino, et al., Stige Milano Srl, Milano, 208 pp.
Idda Mountain ⓘ San Priamo Quarries	[Opal] Stara P., Astolfi M. (1990) - San Priamo - Rivista Mineralogica Italiana, fasc. 1, pp. 51-63
ⓘ Sant'Antioco	[Opal-A var: Opal-AN] Chinellato Matteo and Michael C. Roarke collections
Sicily Agrigento Province ⓘ Licata	[Amber] Jervis, G. (1881) I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Ermanno Loescher, Torino, XXII+539 pp.; Mezzadri, P. (1988) La serie gessoso solfifera della Sicilia e altre memorie geo-minerarie. Roberto De Nicola Editore, Roma, 874 pp.
Caltanissetta Province Milena ⓘ Giona Mine	[Opal] Friedel, G. (1890) Sur la mélanophlogite. Bulletin de la Société Française de Minéralogie, 13, 356-372; Bombicci, L. (1891) Nuove ricerche sulla melanoflogite della miniera Giona presso Racalmuto (Sicilia). Memorie dell'Accademia delle Scienze dell'Istituto di Bologna, serie 5, 1 (1890-91), 711-742.
Enna Province ⓘ Enna	[Amber] Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.
ⓘ Pergusa Lake area	[Amber] Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.
ⓘ Leonforte	[Amber] - Ferrara F. (1805): Sopra l’Ambra Siciliana. In: Memorie sopra il Lago Naftia nella Sicilia Meridionale, sopra l'Ambra Siciliana, sopra il Mele Ibleo e la città d'Ibla Megara, sopra Nasso e Callipoli. Reale Stamperia, Palermo, 73-159. - Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.
Metropolitan City of Catania Catania ⓘ Simeto River mouth	[Amber] (See "simetite" references)
Santa Maria di Licodia ⓘ Santa Maria di Licodia	[Opal-A var: Opal-AN] Sergio Russo Collection
Metropolitan City of Messina Eolie Islands (Aeolian Islands) Lipari ⓘ Lipari Island	[Opal] Russo, M. (2006) Il gesso delle valli del Faurdo e del Caolino (Isola di Lipari, Messina, Sicilia). Micro (notizie mineralogche), 2006, 51-54.
Pianoconte ⓘ Faurdo Valley (Fossa del Faurdo)	[Opal] Russo, M. (2006): Il gesso delle valli del Faurdo [sic!] e del Caolino (Isola di Lipari - ME). MICRO (località), 1/2006, 51-54.
Quattropani ⓘ Kaolin Mine	[Opal] Russo, M. (2006): Il gesso delle valli del Faurdo [sic!] e del Caolino (Isola di Lipari - ME). MICRO (località), 1/2006, 51-54.
Vulcano Island ⓘ La Fossa crater	[Opal] PANICHI U. (1924): Contributo allo studio dei minerali dell'Isola di Vulcano. - Memorie della Società Italiana delle Scienze (detta dei XL) - serie 3 – 19, 3-55.
Porto Levante Faraglioni di Levante ⓘ Faraglione Nico	[Opal] PANICHI U. (1913): Millosevichite, nuovo minerale del Faraglione di Levante, nell'Isola di Vulcano. - Atti R. Acc. Naz. Lincei - serie 5 - Rend. Cl. Sc. Fis. Mat. Nat. - 22, 5 , 303. PANICHI U. (1924): Contributo allo studio dei minerali dell'Isola di Vulcano. - Memorie della Società Italiana delle Scienze (detta dei XL) - serie 3 - 19, 3-55.
ⓘ Grotta dell'Allume	[Opal] P.Forti, M.Panzica La Manna and A.Rossi (1994) The peculiar mineralogic site of the Alum cave (Vulcano, Sicily). Proceedings of the 7th International Symposium on Vulcanospeleology November 1994 p.35-44.
ⓘ Fumarole al Piano (Levante Beach fumaroles)	[Opal] Honnorez, J., Honnorez-Guerstein, B., Valette, J., and Wauschkuhn, A. (1971) Present day formation of an exhalative sulfide deposit at Vulcano (Thyrrhenian Sea), Part II: Active crystallization of fumarolic sulfides in the volcanic sediments of the Baia di Levante. In: Amstutz, G.C., and Bernard, A.J., eds. Ores in Sediments. VIII. International Sedimentological Congress, Heidelberg, August 31 – September 3, 1971. Conference proceedings. Springer Verlag, Berlin - Heidelberg - New York, pages 139-166; Culotta, L., Gianguzza, A., Mannino, M.R., and Orecchio, S. (2007) Polycyclic aromatic hydrocarbons (PAHs) in Vulcano Island (Aeolian Archipelago) mud utilized for therapeutic purpose. Polycyclic Aromatic Compounds, 27, 281-294.
ⓘ Vulcanello	[Opal] PANICHI U. (1924): Contributo allo studio dei minerali dell'Isola di Vulcano. - Memorie della Società Italiana delle Scienze (detta dei XL) - serie 3 - 19, 3-55. QUERCIGH E. (1935): Sul solfoselenio di Vulcano (Isole Eolie). - Rendiconti dell' Accademia delle Scienze Fisiche e Matematiche di Napoli - 32, 3-7. GARAVELLI C.L. (1958): Sulla natura del cosiddetto "solfoselenio" dell'isola di Vulcano. - Periodico di Mineralogia - 27, 1, 159-178.
Metropolitan City of Palermo ⓘ Petralia Soprana	[Amber] Bombicci, L. (1890) La collezione di Ambre Siciliane posseduta dal museo di Mineralogia della R. Università di Bologna (dono del Ministero di pubblica istruzione nel 1889) e nuove considerazioni sull’origine dell’Ambra gialla. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 4, 10 (1889-1990), 473-486.
Ragusa Province ⓘ Pozzallo	[Amber] Giardina G., Passerino G. (1998): Ambra in Provincia di Ragusa. Riv. Mineral. Ital., 22, 2, 50.
Syracuse Province Augusta ⓘ Agnone Bay	[Amber] Scaccianoce, G. (2018) "Simetite". La rara ambra dell'isola di Sicilia. Rivista Mineralogica Italiana, 42, 3 (3-2018), 202-208.
Pachino ⓘ Costa dell'Ambra	[Amber] Scaccianoce, G. (2018) "Simetite". La rara ambra dell'isola di Sicilia. Rivista Mineralogica Italiana, 42, 3 (3-2018), 202-208.
Trapani Province ⓘ Pantelleria Island	[Opal] Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.; Jervis G. (1881): I tesori sotterranei dell'Italia. Vol. 3: Regioni delle Isole. Sardegna e Sicilia. Addenda ai precedenti volumi. Loescher, Torino, XXII+539 pp.
Trentino-Alto Adige (Trentino-South Tyrol) South Tyrol Puster Valley District Badia (Abtei) San Leonardo (San Linêrt; Sankt Leonhard) ⓘ Santa Croce (La Crusc; Heilig Kreuz)	[Amber] - Koken E. (1913): Beiträge zur Kenntnis der Schichten von Heiligenkreuz (Abteital, Südtirol). Abhandlungen der Kaiserlich-Königlichen Geologischen Reichsanstalt, 16, 4, 1-43. - Gianolla P., Roghi G., Ragazzi E. (1998): Upper Triassic amber in the Dolomites (Northern Italy). A paleoclimatic indicator? Rivista Italiana di Paleontologia e Stratigrafia, 104, 381-390. - Ragazzi E., Fedele P., Gianolla P., Roghi G. (2003): L’ambra triassica delle Dolomiti. Riv. Mineral. Ital., 27, 1, 21-22.
Überetsch-Unterland (Oltradige-Bassa Atesina) Aldein (Aldino) Radein (Redagno) ⓘ Bletterbach Gorge	[Amber] Maffi, D., and Maffi, S. (1992): Le più antiche ambre delle Alpi. Paleocronache, 1-1992, 39-48; Trevisani, E., and Ragazzi, E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Trento Province (Trentino) Ala Pilcante ⓘ Val di Serra Quarry	[Opal] Giorgio Bortolozzi, visual identification.
Baselga di Pinè "Le Trote" ("La Trota") ⓘ Erla Mine	[Opal] Ferretti, P., Fassina, B. and Rocchetti, I. (2018) Il giacimento manganesifero della miniera Erla (Baselga di Pinè, TN). I minerali e il sito estrattivo. Rivista Mineralogica Italiana, 42, 4 (4-2018), 246-261.
Canal San Bovo Vanoi Valley Pralongo ⓘ Pralongo granite quarry (Pralongo Quarry; Grisotto Quarry)	[Opal] Ferretti, P., Gualtieri, A., Rocchetti, I., Vecchi, F. (2015): Cava Pralongo. Nuove segnalazioni dalle pegmatiti della Valle del Vanoi (Canal San Bovo, Trento). Rivista Mineralogica Italiana, 49, 3 (3-2015), 164-185.
Castello Tesino ⓘ Cima D'Asta-Campo Regana	[Opal] Ferretti, P., & Masetto, M. (2008). Cima d'Asta. Recenti ritrovamenti nelle pegmatiti del massiccio granitico (Trentino orientale). Rivista Mineralogica Italiana, 4/2008, 210-228.
Pergine Valsugana ⓘ Viarago Mine	[Opal] "Giorgio Bortolozzi (visual identification)"
Riva del Garda ⓘ Monte Brione	[Amber] Stoppani A. (1886): L’ambra nella storia e nella geologia con speciale riguardo agli antichi popoli d’Italia nei loro rapporti colle origini e collo svolgimento della civiltà in Europa. Fratelli Dumolard Editori, Milano, xxi+277 pp. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Roncegno Terme ⓘ Cinquevalli Mine	[Opal] Exel, R. (1987): Guida mineralogica del Trentino e del Sudtirolo. Athesia, Bolzano, 204 pp.
Trento ⓘ Doss Trento	[Amber] - Ragazzi E., Avanzini M., Dieni I., Roghi G., Stefani C. (2012): New amber findings in Northeastern Italy: suggestions for an integrated view on fossil resin raison d’être. In: Bianchi V., Gattolin G., Rigo M. (eds.): Note brevi e riassunti. X Congresso GEOSED “Associazione Italiana per la Geologia del sedimentario”, Feltre, 2-6 Luglio 2012. Rendiconti Online della Società Geologica Italiana, 20, 71-75. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Tuscany Grosseto Province Monterotondo Marittimo ⓘ Mount Leo	[Opal] A.Costantini, G.Pagani (2015) Minerali: bellezze della natura nel parco delle colline metallifere - Tuscan mining geopark . 1-266
ⓘ Santa Fiora	[Opal] No reference listed
Livorno Province Campiglia Marittima ⓘ Botro ai Marmi	[Opal] Biagioni, C., Orlandi, P., Gini, C., Bargellini, C., Gamucci, C., Marinai, V., Nannoni, R. (2013). Botro ai Marmi. I minerali delle miniere Maffei e Montorsi. Rivista Mineralogica Italiana, 1/2013, 63-83.
ⓘ Maffei Mine	[Opal] Nannoni, R., & Marinai, V. (2008). Monte Spinosa. Nuovi ritrovamenti alle miniere Maffei e Montorsi. Rivista Mineralogica Italiana, 2/2008, 98-111.
Campo nell'Elba ⓘ San Piero in Campo	[Opal-A var: Opal-AN] Orlandi, P., & Pezzotta, F. (1997). Minerali dell'Isola d'Elba. Edizioni Novecento Grafico, Bergamo, 249 pp.
ⓘ La Speranza (Pisani's Quarry)	[Opal-A var: Opal-AN] Barsotti, G., & Nannoni, R. (2006). Rocce, minerali e miniere delle isole dell'Arcipelago Toscano. Pacini editore, 152 pp.
ⓘ Rosina vein	[Opal-A var: Opal-AN] Orlandi, P., & Pezzotta, F. (1997). Minerali dell'Isola d'Elba. Edizioni Novecento Grafico, Bergamo, 249 pp.
Sant'Ilario in Campo ⓘ Catri	[Opal] Giuliano Bettini Collection
Capoliveri Cape Calamita Mine ⓘ Macei stope	[Opal] G. Cocco, C. Garavelli, 1954 - Studio di alcuni problemi geochimici relativi al giacimento di ferro di Capo Calamita (Elba) - Rend. Soc. Min. It., 10: 269-350.
ⓘ Punta Rossa stope	[Opal]
Collesalvetti Colognole ⓘ Poggio alle Fate	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Montemassi	[Opal] Sammartino, F. (2013-2014) Primo ritrovamento di Datolite sui Monti Livornesi. Quaderni del Museo di Storia Naturale di Livorno, 25, 25-27.
ⓘ Petrified wood occurrence	[Amber] Sammartino, F. (2015-2016) Primo ritrovamento di ambra sui Monti Livornesi. Nota preliminare. Quaderni del Museo di Storia Naturale di Livorno, 26, 117-120.
Livorno ⓘ Antignano	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Petrified wood occurrence	[Amber] Sammartino, F. (2015-2016) Primo ritrovamento di ambra sui Monti Livornesi. Nota preliminare. Quaderni del Museo di Storia Naturale di Livorno, 26, 117-120.
ⓘ Poggio Corbolone	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
Valle Benedetta ⓘ Via della Sambuca U-V occurrence ("Sambuca")	[Opal] LIBVRNA N°2 September 2021
Rio Rio Marina ⓘ Cape Arco Mine	[Opal] E. Manasse, 1912 - Ricerche petrografiche e mineralogiche sul Monte Arco (Isola d'Elba) - Atti Soc. Tosc. Sc. Nat., Mem. Serie A, 28:118-199.
ⓘ Torre di Rio - Santa Filomena area (Monte della Torre)	[Opal] Barsotti, G., & Nannoni, R. (2006). Rocce, minerali e miniere delle isole dell'Arcipelago Toscano. Pacini editore, 152 pp.
ⓘ Rosignano Marittimo	[Opal] Ref.: Sammartino F., "Minerali miniere e cave dei Monti Livornesi", Comune di Livorno, 2009.
ⓘ Botro dell'Arancio Quarry	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Botro Masaccio quarry	[Opal] Sartori F. (1967) - La wolchonskoite di Castiglioncello (Livorno). Per. Mineral., Roma, 36, 103-124.
ⓘ Castiglioncello	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Castiglioncello Mine	[Opal] Rielli, A., Boschi, C., & Dini, A. (2022). Tectonically driven carbonation of serpentinite by mantle CO2: genesis of the Castiglioncello magnesite deposit in the Ligurian ophiolite of central Tuscany (Italy). Ore Geology Reviews, 105022.
ⓘ Fortullino	[Opal] Lenzi, A. (1996) La melanoflogite di località Fortullino. Informatore. Giornale del Museo di Storia Naturale Rosignano Solvay: 1: 10-13.; Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Gabbro	[Opal] Bonifazi, Marco (2020) Toscana. I minerali di Livorno. I favolosi tesori dei nostri monti. Youcanprint, 276 pages.
ⓘ Buca Fonda quarry	[Opal] https://parcoculturaledicamaiano.toscana.it/le-miniere,-le-mineralizzazioni-ed-i-minerali.php
ⓘ Quartz occurrences	[Opal] https://parcoculturaledicamaiano.toscana.it/le-miniere,-le-mineralizzazioni-ed-i-minerali.php
ⓘ Upper Ugione stream valley	[Opal] Sammartino, F. (2014) I minerali del Torrente Ugione. Codice Armonico 2014. Quinto congresso di scienze naturali. Ambiente toscano, 183-194.
Lucca Province Garfagnana Villa Collemandina ⓘ Sasso Cinturino	[Opal] Barsanti M., 1989. "I granati di Villa Collemandina". Tesi di laurea inedita, Università di Pisa
Vergemoli Fornovolasco ⓘ Fornaccia	[Opal] • Biagioni, C., Orlandi, P., & Bonini, M. (2008). Fornovolasco. Storia e minerali delle miniere di ferro presso Vergemoli (Alpi Apuane). Rivista Mineralogica Italiana, 4/2008, 230-252
Massa-Carrara Province Carrara Miseglia quarrying basin (Miseglia-Fantiscritti quarrying basin; Fantiscritti quarrying basin) Fantiscritti ⓘ Lucchetti Quarry (Strinato B Quarry; Strinato Quarry)	[Opal] Bonaccorsi, E., Merlino, S., and Orlandi, P. (2007) Zincalstibite, a new mineral, and cualstibite: crystal chemical and structural relationships. American Mineralogist, 92, 198-203.
Metropolitan City of Florence Gambassi Terme ⓘ Gambassi Quarry (Borgo alla Collina)	[Opal] · Betti, C., Bazzoni, C., Bernocchi, M., Pagani, G., Ciriotti, M.E., Bittarello, E., Batoni, M., Batacchi, C. (2017): Poggio del Cornocchio e dintorni (Firenze - Pisa - Siena): storia, miniere e minerali di una zona poco conosciuta. Micro, 15, 1, 2-43.
Il Castagno ⓘ La Striscia	[Opal] Betti, C., Bazzoni, C., Bernocchi, M., Pagani, G., Ciriotti, M.E., Bittarello, E., Batoni, M., Batacchi, C. (2017): Poggio del Cornocchio e dintorni (Firenze - Pisa - Siena): storia, miniere e minerali di una zona poco conosciuta. Micro, 15, 1, 2-43.
ⓘ Impruneta	[Opal] Brizzi G., Meli R., 1996. I minerali della formazione ofiolitica dell'Impruneta (FI). Riv. Miner. Ital., 20: 81-98.
ⓘ Carraie Hill	[Opal] Brizzi G., Meli R., 1996 - I minerali della formazione ofiolitica dell'Impruneta (FI). - Riv. Mineral. Ital., 20 1: 81-98.
Montaione ⓘ Iano (Jano)	[Opal] · Betti, C., Bazzoni, C., Bernocchi, M., Pagani, G., Ciriotti, M.E., Bittarello, E., Batoni, M., Batacchi, C. (2017): Poggio del Cornocchio e dintorni (Firenze - Pisa - Siena): storia, miniere e minerali di una zona poco conosciuta. Micro, 15, 1, 2-43.
Montignoso ⓘ Fornaci di Montignoso Quarry (Bi.Bru Quarry)	[Opal] · Betti, C., Bazzoni, C., Bernocchi, M., Pagani, G., Ciriotti, M.E., Bittarello, E., Batoni, M., Batacchi, C. (2017): Poggio del Cornocchio e dintorni (Firenze - Pisa - Siena): storia, miniere e minerali di una zona poco conosciuta. Micro, 15, 1, 2-43.
Pisa Province Montecatini Val di Cecina ⓘ La Sassa	[Opal] Ricci, Giulia, Andrea M. Monti, Renato Pagano, Marco Martini, Luisa Caneve, and Gilberto Artioli. (2021) "Unusual Luminescence of Quartz from La Sassa, Tuscany: Insights on the Crystal and Defect Nanostructure of Quartz" Minerals 11, no. 12: 1345. https://doi.org/10.3390/min11121345
Monteverdi Marittimo Canneto ⓘ Poggio Castiglione	[Opal] Nannoni, R., Capperi, M., 1989. Miniere e minerali della Val di Cecina. Gruppo Mineralogico Cecinese. Tip. Grafiche Favillini, Livorno.
Pomarance ⓘ Monterufoli	[Opal] Brizzi G., Meli R. (1988) - Le pietre silicee della Fattoria di Monterufoli (PI) - Rivista Mineralogica Italiana, Milano, fasc. 3, pp. 101-110
Volterra ⓘ Poggio del Cornocchio	[Opal] Orlandi P., (2005). "Geositi minerari e mineralogici della provincia di Pisa" in La geologia della provincia di Pisa. Cartografia, geositi e banche dati, pp. 55-280, Provincia di Pisa, 2005
ⓘ Sensano	[Opal] Orlandi P., (2005). "Geositi minerari e mineralogici della provincia di Pisa" in La geologia della provincia di Pisa. Cartografia, geositi e banche dati, pp. 55-280, Provincia di Pisa, 2005
Prato Province Prato Monte Ferrato ⓘ Monte Ferrato quarries	[Opal] Brizzi G., Meli R., Olmi F. (1996): I minerali delle ofioliti del Monte Ferrato (Prato). Riv. Mineral. Ital., 20, 4 (4-1996), 217-234.
Siena Province Chiusdino ⓘ Le Cetine di Cotorniano Mine	[Opal] Menchetti, S., Batoni, M., Batacchi, C., Borselli, G., Brogi, A., Ceccantini, L., Fassina, B., Marchesini, M., Rossellini, A. & Ruggieri, G. (2015): Le Cetine di Cotorniano. Miniera e minerali. Associazione Micro-Mineralogica Italiana, Cremona, 354 p.
Murlo Pompana ⓘ Fosso della Chiesa Mine	[Opal] R. Meli (1999): I minerali del Fosso della Chiesa, Murlo (Siena) - Riv. Mineral. Ital., 23, 2: 103-105
Tyrrhenian Sea Southern Tyrrhenian Sea Aeolian Arc seamounts ⓘ Palinuro Seamount	[Opal] Hollis, S. P., Foury, S., Caruso, S., Johnson, S., Barrote, V., & Pumphrey, A. (2021). Lithogeochemical and Hyperspectral Halos to Ag-Zn-Au Mineralization at Nimbus in the Eastern Goldfields Superterrane, Western Australia. Minerals, 11(3), 254.
Umbria Perugia Province Spoleto ⓘ Colle Fabbri	[Opal] Stoppa F., Scordari F., Mesto E., Sharygin V.V. and Bortolozzi G. - Calcium-aluminium-silicate-hydrate "cement" phases and rare Ca-zeolite association at Colle Fabbri, Central Italy (2010). Centr.Eur.J.Geosci. 2 (2), pag. 175-187 .
Terni Province San Venanzo ⓘ Vispi Quarry (incl. Celli; Pian di Celle volcano)	[Opal] "Giorgio Bortolozzi (visual identification)"
Veneto Belluno Province Belluno Borgo Prà ⓘ Ardo Stream	[Amber] - Trevisani E., Ragazzi E., Roghi G. (2011): First report of amber from the Early Eocene Belluno Flysch (Southern Alps, Northern Italy). Bollettino della Società Paleontologica Italiana, 50, 1, 23-28. - Ragazzi E., Avanzini M., Dieni I., Roghi G., Stefani C. (2012): New amber findings in Northeastern Italy: suggestions for an integrated view on fossil resin raison d’être. In: Bianchi V., Gattolin G., Rigo M. (eds.): Note brevi e riassunti. X Congresso GEOSED “Associazione Italiana per la Geologia del sedimentario”, Feltre, 2-6 Luglio 2012. Rendiconti Online della Società Geologica Italiana, 20, 71-75. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32
Cortina d'Ampezzo ⓘ Ra Stua	[Amber] Roghi, G., Ragazzi, E., and Fedele, P. (2004): L’ambra Cretacea delle Dolomiti e delle Prealpi Giulie. Giornate di Paleontologia 2004, Bolzano, 21-23 Maggio, Abstracts Book, 52; Trevisani, E., and Ragazzi, E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
ⓘ Rifugio Dibona	[Amber] Gianolla, P., Roghi, G., and Ragazzi, E. (1998): Upper Triassic amber in the Dolomites (Northern Italy). A paleoclimatic indicator? Rivista Italiana di Paleontologia e Stratigrafia, 104, 381-390; Roghi, G., Gianolla, P., and Ragazzi, E. (2002): Paleobotanical features of Upper Triassic amber in the Southern Alps (Italy). Abstract, 6th European Paleobotany-Palynology Conference, Athens, unpaged; Ragazzi, E., Fedele, P., Gianolla, P., and Roghi, G. (2003): L’ambra triassica delle Dolomiti. Rivista Mineralogica Italiana, 27, 1 (1-2003), 21-22; Roghi G., Ragazzi E., and Gianolla P. (2006): Triassic amber of the Southern Alps (Italy). Palaios, 21, 2, 143-154.
ⓘ Rumerlo	[Amber] von Koken, E. (1913): Beiträge zur Kenntnis der Schichten von Heiligenkreuz (Abteital, Südtirol). Abhandlungen der Kaiserlich-Königlichen Geologischen Reichsanstalt, 16, 4, 1-43; Gianolla, P., Roghi, G., and Ragazzi, E. (1998): Upper Triassic amber in the Dolomites (Northern Italy). A paleoclimatic indicator? Rivista Italiana di Paleontologia e Stratigrafia, 104, 381-390; Ragazzi, E., Fedele, P., Gianolla, P., and Roghi, G. (2003): L’ambra triassica delle Dolomiti. Rivista Mineralogica Italiana, 27, 1 (1-2003), 21-22.
Feltre ⓘ Pont	[Amber] - Ragazzi E., Avanzini M., Dieni I., Roghi G., Stefani C. (2012): New amber findings in Northeastern Italy: suggestions for an integrated view on fossil resin raison d’être. In: Bianchi V., Gattolin G., Rigo M. (eds.): Note brevi e riassunti. X Congresso GEOSED “Associazione Italiana per la Geologia del sedimentario”, Feltre, 2-6 Luglio 2012. Rendiconti Online della Società Geologica Italiana, 20, 71-75. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
ⓘ Sedico	[Amber] - Ragazzi E., Roghi G. (2003): Prima segnalazione di ambra nei sedimenti oligocenici di Salcedo (Vicenza) e di Sedico (Belluno). Studi e Ricerche, Associazione Amici del Museo Civico “G. Zannato”- Museo Civico “G. Zannato”, Montecchio Maggiore, 10, 19-22. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Padova Province Cinto Euganeo Faedo Monte Fasolo ⓘ Case Berton Quarry	[Opal] "Giorgio Bortolozzi (visual identification)"
Galzignano Terme ⓘ Monte delle Basse	[Opal] "Giorgio Bortolozzi (visual identification)"
Torreglia ⓘ Perlite Quarry	[Opal] Fabris, L., Guastoni, A. (2014) Provincia di Padova. In: Zorzi, F., Boscardin, M., (eds.), Minerali del Veneto. Alla scoperta dei tesori della nostra regione. Museo di Storia Naturale e Archeologia di Montebelluna - Treviso, Cierre Edizioni, Sommacampagna, pages 121-141.
Vo' ⓘ Zovon	[Opal] Fabris, L., Guastoni, A. (2014) Provincia di Padova. In: Zorzi, F., Boscardin, M., (eds.), Minerali del Veneto. Alla scoperta dei tesori della nostra regione. Museo di Storia Naturale e Archeologia di Montebelluna - Treviso, Cierre Edizioni, Sommacampagna, pages 121-141.
Verona Province Grezzana ⓘ Bellori	[Amber] Neri, M., Roghi, G., Ragazzi, E., and Papazzoni, C.A. (2013) Segnalazione di ambra giurassica a Bellori (VR), Calcari Grigi, Giurassico inferiore. Giornate di Paleontologia, Perugia 23-25 maggio 2013, Volume dei Riassunti, 51; Trevisani, E., and Ragazzi, E. (2013) L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Vestenanova Bolca ⓘ Pesciara (Pesciara di Bolca; Monte Postale)	[Amber] Trevisani, E., Papazzoni, C.A., Ragazzi, E., and Roghi, G. (2005) Early Eocene amber from the "Pesciara di Bolca" (Lessini Mountains, Northern Italy). Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 3-4, 260-274; Trevisani, E., and Ragazzi, E. (2013) L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Vicenza Province Cornedo Vicentino Spagnago ⓘ Grolla quarry	[Opal] Lapis, 15 (12), 27-32+50.
Laghi ⓘ Contrada Lorenzi	[Opal] Boscardin M., Daleffe A., Rocchetti I., Zordan A. “I minerali nel Vicentino”, Museo “G. Zannato”, Montecchio Maggiore (Vicenza), 2011.
Monte di Malo ⓘ Rossi Quarry	[Amber] Boscardin, M., and Violati Tescari O. (1996) Gemme del Vicentino. Comune di Montecchio Maggiore, Museo Civico “G. Zannato”, Montecchio Maggiore, 114 pp.; Trevisani, E., and Papazzoni, C.A., Ragazzi, E., and Roghi, G. (2005) Early Eocene amber from the "Pesciara di Bolca" (Lessini Mountains, Northern Italy). Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 3-4, 260-274; Trevisani, E., and Ragazzi, E. (2013) L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Montecchio Maggiore San Pietro ⓘ Monte Nero	[Opal] "Giorgio Bortolozzi (visual identification)"
Salcedo ⓘ Chiavon Stream	[Amber] - Ragazzi E., Roghi G. (2003): Prima segnalazione di ambra nei sedimenti oligocenici di Salcedo (Vicenza) e di Sedico (Belluno). Studi e Ricerche, Associazione Amici del Museo Civico “G. Zannato”- Museo Civico “G. Zannato”, Montecchio Maggiore, 10, 19-22. - Trevisani E., Ragazzi E. (2013): L’ambra nelle Alpi Meridionali: stato delle conoscenze. Quaderni del Museo di Storia Naturale di Ferrara, 1, 25-32.
Tonezza del Cimone ⓘ Valle della Neve quarry	[Opal] "Giorgio Bortolozzi (visual identification)"

Japan
Akita Prefecture Yuzawa City Ogachi ⓘ Akinomiya Hot Springs	[Opal] T. Nakanishi, E. Izawa, K. Watanabe (2003) Mineralogical and Geochemical Characteristics of Siliceous Sinter in Japan. Proceedings 25* NZ Geothermal Workshop 2003 pp155-160.
Aomori Prefecture Goshogawara City ⓘ Bonju mine	[Opal] Dr. Matsuo Nambu collection (curated at Geological Survey of Japan)
Chiba Prefecture ⓘ Chōshi City	[Amber] Ryoichi SADANAGA and Michiaki BUNNO (1974) THE WAKABAYASHI MINERAL COLLECTION Bulletin No. 7 The University Museum, The University of Tokyo; Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.
Minamiboso city ⓘ Arakawa	[Opal] Momma, K., Ikeda, T., Nagase, T., Kuribayashi, T., Honma, C., Nishikubo, K., Takahashi, N., Takada, M., Matsushita, Y., Miyawaki, R. and Matsubara, S. (2020) Bosoite, a new silica clathrate mineral from Chiba Prefecture, Japan. Mineralogical Magazine: 84(6): 941-948.; H. Imai collection.
Fukuoka prefecture Tagawa District Kawara ⓘ Sannotake mine	[Opal-A var: Opal-AN] Uehara, S., et al. (2014) Minerals from Kyushu and Yamaguchi. (Fukuoka Mineral Club, 355 pages)
Fukushima Prefecture Date City ⓘ Minowa	[Opal] Chishitsu Chousajo (1902)
ⓘ Hosaka	[Opal] Masutomi Museum specimen (Kyoto)
Ishikawa District ⓘ Ishikawa town (Ishikawa-machi)	[Opal] Chishitsu Chousajo (1902)
Gifu Prefecture Mizunami City ⓘ Tsukiyoshida	[Opal] specimens in several Japanese museums and private collections
Nakatsugawa City ⓘ Hirukawa	[Opal-A var: Opal-AN] Alfredo Petrov collection.
ⓘ Tawara (Tahara)	[Opal-A var: Opal-AN] Alfredo Petrov, field collected, and widespread in innumerable japanese collections.
Gunma Prefecture Agatsuma District ⓘ Okumanza Hot Spring	[Opal] Mineralogical Journal Vol. 20 (1998) , No. 1 pp 1-8
Hiroshima Prefecture Hiroshima City ⓘ Setagawa	[Opal-A var: Opal-AN] alfredo petrov specimens
Hokkaidō Prefecture Iburi Subprefecture Usu District Sobetsu ⓘ Horobetsu sulphur mine	[Opal] Takeo Kato, Takeo Watanabe, Akira Nakamoto (1934) On the sulphur deposits associated with iron sulphide ore, found in the Quaternary Formation of Japan. Japan Journal of Geology and Geography, 15, 3-4, 287-324.
Kushiro Subprefecture Kawakami District Atosanupuri volcano (Iou-zan; Mount Iwo) ⓘ Atosanupuri sulphur mine	[Opal] Katsui, Yoshio (1962) Explanatory text of the Geological map of Japan, scale 1:50,000 - Kutcharo-ko (Abashiri-60), Abstract.
Okhotsk Subprefecture Kitami City ⓘ Kokuriki mine ?	[Opal] Katsu Kaneko (1956) Symposium del Manganeso, XX Congreso Geologico Internacional, Mexico D.F.
Sorachi Subprefecture Mikasa City Ponbetsu ⓘ Sunago coal mine	[Amber] Alfredo Petrov specimen
Tokachi Subprefecture Ashoro District Ashoro-cho (Asyoro-tyo) ⓘ Akan mine	[Opal] Suzuki, J. et al (1957) Journal of the Faculty of Science, Hokkaido University, Ser. 4, 9, 501-518.
Kato District Shikaoi (Shikaoi-Chō) ⓘ Shikaribetsu Lake	[Opal] Amir Akhavan Collection
Hyogo Prefecture Kobe city Kita-ku ⓘ Yamada-cho	[Amber] Ou'e Rikosya specimens
Ibaraki Prefecture Kitaibaraki City ⓘ Hanakawa	[Amber] Ryoichi SADANAGA and Michiaki BUNNO (1974) THE WAKABAYASHI MINERAL COLLECTION Bulletin No. 7 The University Museum, The University of Tokyo
Makabe District Makabe-machi ⓘ Yamanoo	[Opal-A var: Opal-AN] Alfredo Petrov specimens, received from Colorstone Mithrill, Tokyo.
Ishikawa Prefecture Enuma district ⓘ Nata-mura	[Opal] Chishitsu Chousajo (1902)
Komatsu City ⓘ Akase-machi	[Opal] Ryoichi SADANAGA and Michiaki BUNNO (1974) THE WAKABAYASHI MINERAL COLLECTION Bulletin No. 7 The University Museum, The University of Tokyo
ⓘ Yusenji Mine	[Opal] Ryoichi SADANAGA and Michiaki BUNNO (1974) THE WAKABAYASHI MINERAL COLLECTION Bulletin No. 7 The University Museum, The University of Tokyo; Dr Yohachiro Okamoto (1876-1960) collection (curated by the Geological Survey of Japan)
ⓘ Suzu City	[Opal] Hiroaki Tano specimens
ⓘ Menilite occurrence	[Opal] Hiroaki Tano's specimen, and it's known in the Noto Area for many years
Iwate Prefecture Hachimantai City ⓘ Matsuo mine	[Opal] Takeo Kato, Takeo Watanabe, Akira Nakamoto (1934) on the sulphur deposits associated with iron sulphide ore, found in the Quaternary Formation of Japan. Japan Journal of Geology and Geography, 15, 3-4, 287-324.; Iichiro Takahashi (1957) Studies on the Sulphur and Iron-Sulphides Deposits of the Matsuo Mine (2). Mining Geology 7:104-111
ⓘ Kuji City	[Amber] Kuji Amber Museum; American Museum of Natural History (New York); Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.
ⓘ Goishi	[Amber] Kuji Amber Museum; American Museum of Natural History (New York); Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.
Kunohe-gun Noda ⓘ Noda-Tamagawa mine	[Opal] Watanabe, T. (1959) Mineralogical Journal, 2, 6, 408-421
Kagoshima Prefecture Hishikari Au mine ⓘ Main deposit	[Opal] Fulin Zhang, Chengmo Jin, and Qiyun Qing (1986): Geology and Prospecting 22(6), 9-12
Kagoshima District Mishima village ⓘ Satsuma-Ioujima (Satsuma-Iwojima; Iou island)	[Opal] S. Hamasaki (2002) Earth Planets Space 54, 217-229.
ⓘ Higashi Onsen	[Opal] Amir Akhavan Collection
ⓘ Inamuradake	[Opal] Amir Akhavan Collection
ⓘ Iodake (Iwodake; Ioudake)	[Opal] S. Hamasaki (2002) Earth Planets Space 54, 217-229.
ⓘ Main Crater	[Opal]
ⓘ Monogusa	[Opal] Amir Akhavan Collection
ⓘ North-western fumarole field	[Opal]
Kirishima City Makizono ⓘ Sandaidou	[Opal] Alfredo Petrov collection
Kochi Prefecture Kochi City ⓘ Kunimiyama mine	[Opal] Kaneko, K. (1956) Symposium sobre yacimientos de manganeso. Vol. 4, 184 (Mexico, 1956)
Kyoto Prefecture Yosa District Yosa-mura ⓘ Oeyama mine	[Opal] IMAI, N., & OTSUKA, R. (2000). Department of Mineral Industry, School of Science and Engineering, Waseda University, Tokyo, 160 Japan. Palygorskite-Sepiolite: Occurrences, Genesis and Uses, 37, 211.
Mie Prefecture Ise City ⓘ Tsujikuru	[Opal] Kimura, T. & Nampei, H. (1982) Geoscience Magazine, 32, 153-160.
Miyagi Prefecture Katta District Zao ⓘ Enda	[Opal] Dr. Matsuo Nambu collection (curated at Geological Survey of Japan)
ⓘ Onikobe geothermal field	[Opal] Seki, Y. and Okumura, K. (1968) Yugawaralite from Onikobe active geothermal area, Northeast Japan. Jour. Japan. Assoc. Min. Pet. Economic Geology, 60, #1, 27-33.
Nagano Prefecture Chino City ⓘ Suwa mine	[Opal] H. Minato (1953) Koubutsugaku Zasshi, 1, #2, 67
Nagasaki Prefecture Higashisonogi District ⓘ Sonogi mine	[Opal] Dr Yohachiro Okamoto (1876-1960) collection (curated by the Geological Survey of Japan)
Nara Prefecture Uda City ⓘ Yamato Mine (Yamato-suigin Mine)	[Opal] Geology and Mineral Resources of Japan (Geological Survey of Japan, 1960)
Niigata Prefecture Osudo ⓘ Murakami sericite deposit	[Opal] Takahisa Yoshimura & Yujin Ishizuka (1989) Ferrierite in a hydrothermal alteration zone around the murakami sericite deposit. Journal of the Clay Science Society of Japan (in Japanese); 29:179-186
Okayama Prefecture ⓘ Kenzan mine	[Opal] Yamada, S. (2004) Nihonsan-koubutsu Gojuon-hairetsu Sanchi-ichiranhyou (111 pp.)
Maniwa City Teragohchi ⓘ Ohnagusa mine (Onagusa)	[Opal] H. Momoi (1964) Memoirs of the Faculty of Science, Kyushu University, Series D, Geology, 15, #1, 65-72.
Saga Prefecture Karatsu City Hizen-cho ⓘ Mitsukoshi	[Opal-A var: Opal-AN] Miyawaki R, Matsubara S, Yokoyama K, Iwano S, Hamasaki K, Yukinori I (2003) Kozoite-(La), La(CO3)(OH), a new mineral from Mitsukoshi, Hizen-cho, Saga Prefecture, Japan. Journal of Mineralogical and Petrological Sciences 98, 137-141
ⓘ Niikoba	[Opal-A var: Opal-AN] Miyawaki, R., Matsubara, S., Yokoyama, K., Takeuchi, K., Terada, Y., & Nakai, I. (2000). Kozoite-(Nd), Nd (CO3)(OH), a new mineral in an alkali olivine basalt from Hizen-cho, Saga Prefecture, Japan. American Mineralogist, 85(7-8), 1076-1081.
Kyuuragi-machi ⓘ Kyuuragi mine (Kyuragi mine) ?	[Opal] Katsu Kaneko (1956) Symposium del Manganeso, XX Congreso Geologico Internacional, Mexico D.F.
Shiga Prefecture Otsu City ⓘ Tanakami-yama (Tanokami-yama)	[Opal-A var: Opal-AN] Nakatsugawa Mineral Museum (Gifu Prefecture, Japan)
Ritto City ⓘ Ioi mine	[Opal] Hiroaki Tano's collection
Shizuoka Prefecture Shimoda City Rendaiji ⓘ Kawazu mine (Rendaiji mine; Rendaizi mine)	[Opal] (unpublished species lists maintained by local collectors; needs confirmation)
Tokyo Metropolis Hachijō Subprefecture ⓘ Aogashima	[Opal] Alfredo Petrov - field observations, 4-2014
Hachijo ⓘ Hachijo Island	[Opal-A var: Opal-AN] field collected by Alfredo Petrov, 12-2011
Hachioji City ⓘ Asagawa	[Amber] Alfredo Petrov specimen
Ogasawara Subprefecture Ogasawara Islands Chichijima Group Chichi Island (Chichijima) ⓘ Kita-hatsuneura (2)	[Opal] Mineralogical Journal Vol. 11 (1982) , No. 1 pp1-14
ⓘ Susaki	[Opal] Mineralogical Journal Vol. 11 (1982) , No. 1 pp1-14
Volcano Islands Iwo Jima (Iou-to; Iou Island; Iwojima; Iou-jima; Naka-Iou-jima) ⓘ Suribachiyama	[Opal] Gordon A. MacDonald (1948) Petrography of Iwo Jima. Bulletin of the GSA, 59, 1009-1018.
Toyama Prefecture Kaminiikawa district ⓘ Tateyama hot springs	[Opal] Chishitsu Chousajo (1902)
Yamagata Prefecture Tsuruoka City ⓘ Irakawa (Isogawa)	[Opal] Mizota (1969) Ganseki-Koubutsu-Koshogaku Zasshi, 62, 329-338.
Yamaguchi Prefecture Mine city ⓘ Ofuku mine (Yamato mine)	[Opal] Dr Yohachiro Okamoto (1876-1960) collection (curated by the Geological Survey of Japan)
Yamanashi Prefecture ⓘ Kinpuzan mining district	[Opal] Chishitsu Chousajo (1902)

Jordan
Amman Governorate Transjordan Plateau Daba-Siwaqa complex ⓘ Daba	[Opal] Pitty, A. F., & Alexander, W. R. (2010). A natural analogue study of cement buffered, hyperalkaline groundwaters and their interaction with a repository host rock IV: an examination of the Khushaym Matruk (central Jordan) and Maqarin (northern Jordan) sites. NDA-RWMD Technical Report, NDA, Moors Row, UK.
Hashem region Lisdan-Siwaga Fault Siwaga Tulul al Hammam ⓘ Unnamed marble quarries	[Opal] Sokol, E.V.; Kokh, S.N.; Seryotkin, Y.V.; Deviatiiarova, A.S.; Goryainov, S.V.; Sharygin, V.V.; Khoury, H.N.; Karmanov, N.S.; Danilovsky, V.A.; Artemyev, D.A. (2020) Ultrahigh-Temperature Sphalerite from Zn-Cd-Se-Rich Combustion Metamorphic Marbles, Daba Complex, Central Jordan: Paragenesis, Chemistry, and Structure. Minerals: 10(9): 822.
Irbid Governorate Maqarin area ⓘ Yarmouk river	[Opal] Khoury, H. N., Salameh, E., & Abdul-Jaber, Q. (1985). Characteristics of an unusual highly alkaline water from the Maqarin area, northern Jordan. Journal of Hydrology, 81(1), 79-91.
Jerash Governorate Jerash ⓘ Jerash lignite occurrence	[Amber] Dill, H. G., Kus, J., Abed, A. M., Sachsenhofer, R. F., & Abul Khair, H. (2009). Diagenetic and epigenetic alteration of Cretaceous to Paleogene organic-rich sedimentary successions in northwestern Jordan, typical of the western margin of the Arabian Plate. GeoArabia, 14(2), 101-140.
Madaba Governorate ⓘ Wadi Zerka	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)

Kazakhstan
Aktobe Region Kargaly ⓘ Kempirsay massif	[Opal] Korobkin, V., Samatov, I., Chaklikov, A., & Tulemissova, Z. (2022). Peculiarities of Dynamics of Hypergenic Mineral Transformation of Nickel Weathering Crusts of Ultramafic Rocks of the Kempirsay Group of Deposits in Western Kazakhstan. Minerals, 12(5), 650.
Khromtau ⓘ Kempyrsay	[Opal] Bespaev H.A., Uzhkenov B.S., Aliaskarov S.A., Egembaev K.M. (Almaty, 1999) Gemstones of Kazakhstan, Reference book. Volume 1. Deposits and occurrences of precious and semiprecious stones.
Martuk ⓘ Voznesenovka	[Opal] Oleg Lopatkin collection
Mugalzhar ⓘ Kokmola	[Opal] Bespaev H.A., Uzhkenov B.S., Aliaskarov S.A., Egembaev K.M. (Almaty, 1999) Gemstones of Kazakhstan, Reference book. Volume 1. Deposits and occurrences of precious and semiprecious stones.
East Kazakhstan Region Tarbagatai Range Akzhaylyautas Mts (Akzhailyautas Mts; Akjaylautas Mts; Akzhalautas Mts) ⓘ Verkhnee Espe Massif (Verkhnee Espe deposit)	[Opal] Bailey, J. C: Formation of cryolite and other aluminofluorides: A petrologic review. Bull. geol. Soc. Denmark, vol. 29, pp. 1-45. Copenhagen, June 10th, 1980.
Jambyl Region Moiynkum Chu-Ili Mountains ⓘ Kyzylsai Mo-U deposit	[Opal] Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
Karaganda Region Aktogay ⓘ Batystau polymetallic deposit	[Opal] Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
Karazhal Betpakdala Desert (Bet-Pak-Dal Desert) ⓘ Kara-Oba W deposit	[Opal] Ermilova, L. P. & Senderova, V. M. (1961): Betpakdalite, a new mineral from the oxidation zone of the wolframite ore deposit of Karaoba (Central Kazakhstan). Zapiski Vserossiiskogo Mineralogicheskogo Obshchestva 90, 425-430. (in Russian) ; Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
Karkaraly ⓘ Ken'-Choku deposit (Ken'-Cheku; Ken'-Shoko)	[Opal] Pavel M. Kartashov data
Shet ⓘ Ken-Choku (Kenshoky) deposit	[Opal] According reports of geological service of USSR
Ulytau Mayatas ore region ⓘ Maike Occurrence	[Opal] Levin, V. L., Stepanets, V. G., Li, E. S., Bekenova, G. K., & Khakimdzhanov, M. S. (2021). Finding of Re Sulfides in Copper-Sulfide Ores of the Maike Occurrence, Ulytau, Central Kazakhstan. Geology of Ore Deposits, 63(8), 830-841.
Zhanaarka ⓘ Pstan	[Opal] Gems of Kazakhstan, - textbook, Almaty, 1999, v.1, pp. 71-73 (in Rus.)
Pavlodar Region May ⓘ May agate occurrence (Mayskoye agate occurrence)	[Opal] Bespaev, Kh.A., Uzhkenov, B.S., Aliaksarov, S.A., and Egembaev, K.M. [Беспаев, Х.А., Ужкенов, Б.С., Алиаскаров, С.А., и Егембаев, К.М.] (2001) Gemstones of Kazakhstan. Reference book. Volume II. Semi-precious and ornamental stones [Самоцветы Казахстана. Справочник. Том II. Ювелирно-поделочные и поделочные самоцветы]. Information-Analytical Center for Geology and Mineral Resources of the Republic of Kazakhstan [Информационно-аналитический центр геологии и минеральных ресурсов Республики Казахстан], Almaty, pages 106-107 (in Russian).
ⓘ Shymkent City	[Amber] Soriano, C. (2009). First record of the family Belidae (Insecta, Coleoptera) in amber. New genus and species from the uppermost Albian amber of France. Geodiversitas, 31(1), 99-104.

Kenya
Baringo County ⓘ Lake Bogoria (Hannington Lake)	[Opal] Owen, R. A., Owen, R. B., Renaut, R. W., Scott, J. J., Jones, B., & Ashley, G. M. (2008). Mineralogy and origin of rhizoliths on the margins of saline, alkaline Lake Bogoria, Kenya Rift Valley. Sedimentary Geology, 203(1-2), 143-163.
Kajiado County Mount Suswa (Suswa Volcano) ⓘ Cave No. 13	[Opal] Forti, P., Galli, E., Rossi, A. (2004) Minerogenesis of volcanic caves of Kenya. International Journal of Speleology: 32: 3-18.
Makueni County Chyulu Hills ⓘ Leviathan Cave	[Opal] Forti, P., Galli, E., & Rossi, A. (2003). Minerogenesis of volcanic caves of Kenya. International Journal of Speleology, 32(1), 1.
Taita-Taveta County Voi Tsavo National Park ⓘ Shetani Lava Cave	[Opal] Forti, P., Galli, E., & Rossi, A. (2003). Minerogenesis of volcanic caves of Kenya. International Journal of Speleology, 32(1), 1.

Kosovo
Ferizaj District Shtime Glavika ⓘ Glavika Laterite Mine	[Opal] Mineral deposits and mining districts of Serbia Compilation map and GIS databases, 2002, J. Monthel, P. Vadala, J.M. Leistel, F. Cottard with the collaboration of M. Ilic, A. Strumberger, R. Tosovic, A. Stepanovic, March 2002 BRGM/RC-51448-FR; Buletini i Shkencave Gjeologjike 2012
ⓘ Pristina District	[Opal] Vik Vanrusselt collection
Drenas (Glogovac) Çikatovë e Vjetër (Cikatovo) ⓘ Cikatovo Laterite Mine	[Opal] Mineral deposits and mining districts of Serbia Compilation map and GIS databases, 2002, J. Monthel, P. Vadala, J.M. Leistel, F. Cottard with the collaboration of M. Ilic, A. Strumberger, R. Tosovic, A. Stepanovic, March 2002 BRGM/RC-51448-FR
Lipjan ⓘ Gllavica Mine	[Opal] Miladinovic, Z., Simic, V., Jelenkovic, R., & Ilic, M. (2016). Gemstone deposits of Serbia. Geologica Carpathica, 67(3), 211.
ⓘ Goleshi Mine	[Opal] Ilich, M., & Toshovich, R. (2002). Geology and Origin the Golesh Vein Magnesite Deposit: a Brief Survey. Masurenko, C. (2019) Business Development of the Goleshi Mine: Scoping Study Report.

Latvia	[Amber]

Kurzeme Region ⓘ South Kurzeme Municipality	[Amber] Dreimanis A., Liepiņš P. 1942. Latvijas minerāli un ieži. Rīga, Universitātes apgāds, 312 lpp.
ⓘ Ventspils Municipality	[Amber] Dmitry Vorobjov's collection
Vidzeme Region Ādaži Municipality ⓘ Carnikava Parish	[Amber] Dmitry Vorobjov's collection
ⓘ Carnikava Beach	[Amber] Dmitry Vorobjov's collection

Lebanon
South Governorate ⓘ Jezzine District	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)
ⓘ Dar al-Baidha (Dar el Beida)	[Amber] George O. Poinar (1992) Life in Amber. (Stanford University Press)

Libya
Tripoli District ⓘ Tripoli	[Opal] Robert D. Crangle (2008) Diatomite. Minerals Yearbook, 2008 USGS

Lithuania
ⓘ Curonian Lagoon	[Amber] ; GEOCHRONOMETRIA 33 (2009), pp 33-36
Klaipėda County Klaipeda District Municipality Klaipeda ⓘ Curonian Spit	[Amber] Dmitry Vorobjov's collection
Neringa Municipality Neringa ⓘ Juodkrantė	[Amber] GEOCHRONOMETRIA 33 (2009), pp 33-36
Telšiai County Varniai ⓘ Lake Lukstas	[Amber] Ellen Chivers Davies (1937) A wayfarer in Estonia, Latvia and Lithuania

Madagascar
Alaotra-Mangoro Ambatondrazaka Ambatosoratra ⓘ Ambatosoratra pegmatite	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Amoron'i Mania Ambatofinandrahana Mandrosonoro Ambatovita ⓘ Sakavalana mine	[Opal] Knut Eldjarn specimen & photo
Mangataboahangy ⓘ Antsakoanimanta (Mangatobangy)	[Opal] Pezzotta, F. (1996): Mangatobangy. Amethyst-Zepter aus Madagascar. Lapis 21 (9), pp 32-35
ⓘ Volonandrongo (Volonondrongo)	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Geologique A. 1871
Ambositra Sahatsiho Ambohimanjaka Manandona Valley ⓘ Antandrokomby pegmatite	[Opal] Ranorosoa, N. (1986): Etude mineralogique des pegmatites du champ de la Sahatany, Madagascar. These de Doctorat de l`Universite Paul Sabatier, Toulouse
Manandriana District Andakatany Ambatofangehana ⓘ Pachoud Mine	[Opal] Lacroix, A. (1899): Matériaux pour la Minéralogie de Madagascar. IV. Brochantite d'Ambatofangehana (Province d'Ambositra). Bulletin du Muséum national d'histoire naturelle 5 : 318-319
Androy Ambovombe-Androy Ampamata ⓘ Mandrovato phlogopite mine	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Tsihombe Tsihombe Commune ⓘ Anjanikaima phlogopite deposit	[Opal] Besairie, H. (1966): Les Gites Minéraux de Madagascar. Annales Géologiques de Madagascar, Tananarive, 34, p. 335
ⓘ Sakamasy phlogopite mine	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Anosy Amboasary Sud District Behara ⓘ Vohibola phlogopite deposit	[Opal] Michel Arliguie photo and specimen
ⓘ Tsivory	[Opal] Eliana Intruglio's mineral collection
Betroka District Beampombo II ⓘ Beapompo II workings	[Opal] Daniil V. Popov, Richard A. Spikings, Stéphane Scaillet, Gary O'Sullivan, David Chew, Eszter Badenszki, J. Stephen Daly, Théodore Razakamanana, Joshua H.F.L. Davies (2020) Diffusion and fluid interaction in Itrongay pegmatite (Madagascar): Evidence from in situ 40Ar/39Ar dating of gem-quality alkali feldspar and UPb dating of protogenetic apatite inclusions. Chemical Geology. 556 (2020) 119841. https://doi.org/10.1016/j.chemgeo.2020.119841.
Benato Toby ⓘ Benato phlogopite mines	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Mahasoa Est ⓘ Itrongay (Itrongahy)	[Opal] Lacroix, A. (1922): Mineralogie de Madagascar, Tome I. Géologie-Minéralogie descriptive. A.Challamel (Éditeur), Paris. 624p. (p.558-561)
Atsimo-Andrefana Betioky Lazarivo ⓘ Vohitsevo	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Atsimo-Atsinanana Befotaka Marovitsika Sud Bemia ⓘ Fire Opal Occurrence	[Opal] Simoni, M., Caucia, F., Adamao, I. & Galinetto, P. (2010): New occurrence of fire opal from Bemia, Madagascar. Gems & Gemmology. 46 (2), 114-121
Vakinankaratra Antsirabe I District ⓘ Mangarivotra	[Opal-A var: Opal-AN] Knut Edvard Larsen collection # M-190
Antsirabe II District Ibity Sahatany Valley ⓘ Manjaka	[Opal-A var: Opal-AN] Knut Edvard Larsen collection, inventory nr. M-800
ⓘ Vohidahy	[Opal] Ranorosoa, N. (1986): Etude mineralogique des pegmatites du champ de la Sahatany, Madagascar. These de Doctorat de l`Universite Paul Sabatier, Toulouse
Vinaninkarena Anjanamanjaka ⓘ Vatovory (Vinaninkarena Uranium deposit)	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
ⓘ Faratsiho	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871
Faratsiho Commune ⓘ Unnamed Opal locality	[Opal] Behier, J. (1963): Carte mineralogique de Madagascar. Archive Service Géologique Madagascar. A 1871

Malaysia
Sarawak Kapit Division ⓘ Merit Block coal deposits	[Amber] Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56.
Kuching Division Bau ⓘ Gading deposit	[Opal] Yajima, S. (1960). Metacinnabar from Sarawak and Japan, with Reference to Its Stability Relations to Cinnabar. Mineralogical Journal, 3(1), 9-18.
Miri Division ⓘ Niah Great Cave (Gunong Jerneb)	[Opal] Bridge, P.J., Robinson, B.W. (1983) Niahite - a new mineral from Malaysia. Mineralogical Magazine: 47: 79-80.

Mali
Kayes Region Nioro du Sahel Cercle ⓘ Opal occurrence	[Opal]

Marshall Islands
ⓘ Wōdejebato Guyot	[Opal] Rex, R. W. (1967). Authigenic silicates formed from basaltic glass by more than 60 million years contact with sea water, Sylvania Guyot, Marshall Islands. In Clays and Clay Minerals: Proceedings of the Fifteenth Conference, Clay Minerals Society (pp. 195-203).

Mauritania
Tiris Zemmour Region Bir Lemjed ⓘ MGS No. BL6844	[Opal] Mauritanian Geological Survey (1995) database

Mexico	[Opal] Gübelin, E., Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).; Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.

Baja California Tijuana Municipality Tijuana ⓘ Rodriguez Dam	[Opal] Rob Lavinsky
Baja California Sur Loreto Municipality ⓘ Santa Rosa	[Opal] RODRIGUEZ-DIAZ, Augusto Antonio et al. Metallogeny of the Santa Rosa manganese deposit, Baja California Sur, Mexico. Bol. Soc. Geol. Mex [online]. 2010, vol.62, n.1, pp. 141-159
Mulegé Municipality ⓘ Bahía Concepcio´n	[Opal] Canet, C., Prol-Ledesma, R. M., Proenza, J. A., Rubio-Ramos, M. A., Forrest, M. J., Torres-Vera, M. A., & Rodríguez-Díaz, A. A. (2005). Mn–Ba–Hg mineralization at shallow submarine hydrothermal vents in bahía Concepción, Baja California Sur, México. Chemical Geology, 224(1-3), 96-112. Rodriguez, Augusto & Canet, Carles & Villanueva, Ruth & Chacon, Elizabeth & Gervilla, Fernando & Velasco-Tapia, Fernando & Gámez, Esther & González-Partida, Eduardo & Casas-García, Raymundo & Linares-López, Carlos & Pérez-Zárate, D.. (2019). Recent Mn-Ag deposits in coastal hydrothermal springs in the Baja California Peninsula, Mexico. Mineralium Deposita. 54. 10.1007/s00126-018-0846-9.
Chiapas San Cristobal de Las Casas Municipality San Cristobal de Las Casas ⓘ Teopisca	[Amber] Bryant, D. D. (1983). A recently discovered amber source near Totolapa, Chiapas, Mexico. American Antiquity, 354-357.
ⓘ Simojovel Municipality	[Amber] https://www.gemologyonline.com/David_Gibson/photos.php
Totolapa Municipality ⓘ Totolapa	[Amber] Bryant, D. D. (1983). A recently discovered amber source near Totolapa, Chiapas, Mexico. American Antiquity, 354-357.
ⓘ Chihuahua	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Aldama Municipality ⓘ Estacion Trancas	[Opal] Peter Megaw collection
ⓘ Las Choyas	[Opal] Cross, B. & Culp Zeitner J. (2006), Geodes Natures Treasures, P.23
Peña Blanca District Sierra Peña Blanca ⓘ Margaritas No. 1 Mine	[Opal] George-Aniel, B., Leroy, J.L., Poty, B. (1991) Volcanogenic uranium mineralizations in the Sierra Pena Blanca District, Chihuahua, Mexico; three genetic models. Economic Geology: 86(2): 233–248.
ⓘ Nopal No. 1 Mine	[Opal] http://www.swri.org/4org/d20/ghs/PBlanca/mineral.html; Econ Geol (1991) 86:233-248; Schindler, M. et al. (2010): Geochim. Cosmochim. Acta 74, 187-202.; Othmane, G., Allard, T., Menguy, N., Morin, G., Esteve, I., Fayek, M., & Calas, G. (2013). Evidence for nanocrystals of vorlanite, a rare uranate mineral, in the Nopal I low-temperature uranium deposit (Sierra Peña Blanca, Mexico). American Mineralogist, 98(2-3), 518-521.
Chínipas Municipality Palmarejo ⓘ Guadalupe deposit	[Opal] Sotelo, C. M. (2016). Geology and mineralization controls surrounding the Palmarejo mining district-A compilation of remote and hands on exploration techniques. The University of Texas at El Paso.
Manuel Benavides Municipality San Carlos ⓘ Apex mine	[Opal] Hewitt, W.P. AIME Zinc Proceedings 1971
ⓘ Tres Marias mine	[Opal] Mineralium Deposita, 44 (2009) 363-370
Saucillo Municipality Naica ⓘ Naica Mine	[Opal] Gazquez, et al., 2016, The Caves of Naica: a decade of research: Boletin geologico y Minero 1`27 (1) 147-`63
Coahuila Cuatro Ciénegas Municipality Cuatro Ciénegas (Cuatrociénegas de Carranza; Venustiano Carranza) Limestone caves ⓘ Rancho Guadalupe cave	[Opal] Forti, P. et al. (2006): ACTA CARSOLOGICA 35/1, 79–98.
Sierra Mojada Municipality Sierra Mojada ⓘ Fortuna Mine	[Opal-A var: Opal-AN] Panczner(1987):228-286.
Durango Coneto de Comonfort Municipality América-Sapioris District (Potrillos) Sierra de San Francisco Potrillos ⓘ Artroyos Mine	[Opal-A var: Opal-AN] Yves Masson photo
Coneto de Comonfort ⓘ Barranca Mine	[Opal] No reference listed
Durango Municipality Victoria de Durango ⓘ Cerro de Mercado Mine	[Opal-A var: Opal-AN] No reference listed
Mapimí Municipality ⓘ Mapimí	[Opal] J.Hyrsl (2012) Gemstones of Peru, p. 62
Mezquital Municipality Mezquital ⓘ San Francisco del Oro Mine	[Opal] Panczner (1987): 286.
Pánuco de Coronado Municipality Francisco I. Madero ⓘ La Esperanza Mine	[Opal] [AmMin 85:263]
Guanajuato Cuerámaro Municipality Cuerámaro ⓘ Buenos Aires Mine	[Opal] Panczner(1987):286.
Pénjamo Municipality Pénjamo ⓘ Buenos Aires Mine	[Opal] Panczner(1987):287.
Santa Catarina Municipality Santa Catarina Cerro de las Fajas ⓘ Santín Mine	[Opal] Panczner (1987): 287.; Am Min (1955) 40 (1-2), 64-69
ⓘ Hidalgo	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Zimapán Municipality ⓘ Zimapán	[Opal]
ⓘ Lomo Deltoro Mine	[Opal] Panczner, W.D. (1987) Minerals of Mexico. New York : Van Nostrand Reinhold, 459 pgs (93-396).
ⓘ Jalisco	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Magdalena Municipality La Amazata ⓘ Amazata Mine	[Opal] Panczner(1987):287.
ⓘ Estancia Mine	[Opal] Panczner(1987):287.
ⓘ Magdalena	[Opal]
ⓘ Tepucanapa Mine	[Opal] Panczner (1987): 287.
ⓘ Unica Mine	[Opal] Panczner (1987): 287.
San Andrés ⓘ Mara Mine	[Opal] Panczner(1987): 288.
San Simón ⓘ Chela Mine	[Opal] Panczner(1987):288.
ⓘ San Simón Mine	[Opal] Panczner (1987): 288.
San Cristóbal de la Barranca El Salvador ⓘ Cobano Mine	[Opal] Panczner(1987):288.
ⓘ Hornitos Mine	[Opal] Panczner(1987):288.
Mexico ⓘ Popocatepetl Volcano	[Opal] Curtis, N.J.; Gascooke, J.R.; Johnston, M.R.; Pring, A. (2020) A Review of the Classification of Opal with Reference to Recent New Localities. Minerals 2019, 9, 299.
Temascaltepec Municipality Temascaltepec de González (Temascaltepec) ⓘ La Guitarra mine (La Guitarra deposit)	[Opal] Camprubi, A., Canals, A., Cardellach, E., Prol-Ledesma, R.M., Rivera, R., 2001, The La Guitarra Ag-Au low-sulfidation epithermal deposit, Temascaltepec district, Mexico: vein structure, mineralogy, and sulfide-sulfosalt chemistry. Society of Economic Geologists Special Publication, v. 8, p. 133-158.
Michoacan Uruapan Municipality ⓘ Paricutin volcano	[Opal] Fritsch, E., Gaillou, E., Ostroumov, M., Rondeau, B., Devouard, B., Barreau, A. (2004) Relationship between nanostructure and optical absorption in fibrous pink opals from Mexico and Peru. European Journal of Mineralogy, 16, 743-752
Nayarit La Yesca Municipality La Yesca ⓘ Buena Vista Mine	[Opal] Panczner(1987):288.
Xalisco Municipality La Curva ⓘ Divisadero Mine	[Opal] Panczner(1987):288.
Puebla Ixtacamaxtitlán Municipality Ixtacamaxtitlán ⓘ Ixtacamaxtitlán kaolinite deposit	[Opal] Tritlla, J., Camprubí, A., Morales‐Ramírez, J. M., Iriondo, A., Corona‐Esquivel, R., González‐Partida, E., ... & Carrillo‐Chávez, A. (2004). The Ixtacamaxtitlán kaolinite deposit and sinter (Puebla State, Mexico): a magmatic‐hydrothermal system telescoped by a shallow paleoaquifer. Geofluids, 4(4), 329-340.
ⓘ Tuligtic Cu deposit	[Opal] Tritlla J., Morales J.M., Camprubí A., Iriondo A., Corona-Esquivel R., González-Partida E., Levresse G., and Carrillo-Chávez A. A 2004. The ixtacamaxtitlan kaolinite deposit and sinter (Puebla state, Mexico): a magmatic-hydrothermal system telescoped by shallow paleoaquifer. Geofluids, 4, 4, 329.
ⓘ Queretaro	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Amealco Municipality Amealco ⓘ La Purísima Mine	[Opal] Panczner (1987): 288.
ⓘ Colón (Columbus) Municipality	[Opal]
Ezequiel Montes Municipality Ezequiel Montés ⓘ Guadalupana Mine	[Opal] Panczner(1987):289.
ⓘ San Juan del Río Municipality	[Opal]
Tequisquiapan Municipality La Trinidad ⓘ Carbonera Mine	[Opal] Rob Lavinsky
ⓘ San Luis Potosí	[Opal-A var: Opal-AN] No reference listed
ⓘ Mexquitic de Carmona Municipality	[Opal-A var: Opal-AN] Cook, R.B. (2013) Connoisseur's Choice: Buergerite (Fluor-buergerite) Mexquitic, San Luis Potosi, Mexico. Rocks & Minerals, 88, #5, 442-446.
Villa de Arriaga Municipality ⓘ Tepetate	[Opal-A var: Opal-AN] various added photos
Villa de Reyes Municipality ⓘ La Ventilla	[Opal] Panczner, W.D. (1987) Minerals of Mexico. Van Nostrand Reinhold Company, New York, 459 pp.
Sonora Moctezuma Municipality Moctezuma ⓘ Candelaria mine (Candelaria prospect)	[Opal] Carles Curto specimen
Veracruz ⓘ Tamiahua Lagoon	[Opal] Porras-Toribio, Israel, Teresa Pi-Puig, Ruth E. Villanueva-Estrada, Marco A. Rubio-Ramos, and Jesús Solé. (2022) "Mineralogy, Geochemistry, and Stable Isotopes (C, O, S) of Hot Spring Waters and Associated Travertines near Tamiahua Lagoon, Veracruz, Gulf of Mexico (Mexico)" Minerals 12, no. 7: 822. https://doi.org/10.3390/min12070822
Zacatecas ⓘ Villa García Municipality	[Opal-A var: Opal-AN] Van King
El Copetillo ⓘ Mina Veronica	[Opal-A var: Opal-AN] Rolf Luetcke

Middle East
ⓘ Hatrurim Formation	[Opal] Gross, S. (1977): The Mineralogy of the Hatrurim Formation, Israel. Geological Survey of Israel, Bulletin no. 70, 80 pp.

Mongolia
Dornogovi Province ⓘ Ulugei	[Opal] Pavel M. Kartashov data
Ömnögovi Province Khanbogd District ⓘ Khan Bogd Peralkaline Granite	[Opal] Kynicky, J., Chakhmouradian, A.R., Xu, C., Krmicek & Galilova, M. (2011): Distribution aand evolution of zirconium mineralization in peralkaline granites and associated pegmatites of the Khan Bogd Complex, southern Mongolia. Canadian Mineralogist. 49, 947-965.

Morocco
Drâa-Tafilalet Region Ouarzazate Province Amerzgane Cercle Amerzgane Caïdat Imini area ⓘ Asif Amergou	[Opal] Jewel Tunnel specimens obtained by Rock Currier
Tinghir Province Tinghir Cercle Imiter mining district ⓘ Igoudrane mine	[Opal-A var: Opal-AN] Samira, E., Christine, B. M., Michel, C., Alexandre, T., Philippe, B., & Lhou, M. The Igoudrane Ag-Hg Deposit-Morocco: Mineralogy and Ag-mineralizing Fluid.
Zagora Province Agdz Cercle Tansifite Caïdat Aït Ahmane ⓘ Vein No. 54	[Opal] Favreau, G. and Dietrich, J. E. (2006). Die Mineralien von Bou Azzer. Lapis 31(7/8), 27-68
ⓘ Vein No. 59	[Opal] Favreau, G. and Dietrich, J. E. (2006). Die Mineralien von Bou Azzer. Lapis 31(7/8), 27-68
ⓘ Tachgagalt Mine	[Opal] FAVREAU G. & DIETRICH J.E. (2006) Tachgagalt (Maroc), Le Cahier des Micromonteurs, 93, 37-71. (in French)
Marrakesh-Safi Region El Kelaâ des Sraghna Province ⓘ Sidi Rahal	[Opal] On quartz specimens field-collected by Mark Mauthner.

Myanmar	[Amber] Szwedo, J. (2002). Amber and amber inclusions of planthoppers, leafhoppers and their relatives (Hemiptera, Archaeorrhyncha et Clypaeorrhyncha). Zikaden. Leafhoppers, planthoppers and cicadas (Insecta: Hemiptera: Auchenorrhyncha). Denisia, 4, 37-56. Shi, Zhaotong, Chenxing Xin, and Yamei Wang. (2023) "Spectral Characteristics of Unique Species of Burmese Amber" Minerals 13, no. 2: 151. https://doi.org/10.3390/min13020151

Kachin State Myitkyina District ⓘ Hukawng Valley	[Amber] Cruickshank, R. D., & Ko, K. (2003). Geology of an amber locality in the Hukawng Valley, northern Myanmar. Journal of Asian Earth Sciences, 21(5), 441-455. Shi, Zhaotong, Chenxing Xin, and Yamei Wang. (2023) "Spectral Characteristics of Unique Species of Burmese Amber" Minerals 13, no. 2: 151. https://doi.org/10.3390/min13020151
ⓘ Tanai Township (Tanaing Township)	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Maingkwan	[Amber] Cruickshank, R. D., & Ko, K. (2003). Geology of an amber locality in the Hukawng Valley, northern Myanmar. Journal of Asian Earth Sciences, 21(5), 441-455.
Tanai ⓘ Amber diggings	[Amber] numerous well-labelled specimens on sale at Kyoto show, 2010
Magway Region Gangaw District ⓘ Tilin	[Amber] Shi, Zhaotong, Chenxing Xin, and Yamei Wang. (2023) "Spectral Characteristics of Unique Species of Burmese Amber" Minerals 13, no. 2: 151. https://doi.org/10.3390/min13020151 Zheng, D., Chang, S.C., Perrichot, V., Dutta, S., Rudra, A., Mu, L., Thomson, U., Li, S., Zhang, Q., Zhang, Q. and Wong, J., (2018) A Late Cretaceous amber biota from central Myanmar. Nature communications, 9(1), pp.1-6.
ⓘ Sagaing Region	[Amber] Nyunt, T.T., Cho, C., Kyaw, N.B.B., Krishnaswamy, M., Ying, L.H., Sun, T.T. & Chanmuang N., C. (2021): Geology, occurrence and gemmology of Khamti amber from Sagaing region, Myanmar. Thai Geoscience Journal, 2(2), 61-71.
Hkamti District Hkamti Township (Khamti Township) ⓘ Kandi amber mining area	[Amber] Shi, Zhaotong, Chenxing Xin, and Yamei Wang. (2023) "Spectral Characteristics of Unique Species of Burmese Amber" Minerals 13, no. 2: 151. https://doi.org/10.3390/min13020151
ⓘ Pat-tar Bum amber mining area	[Amber] Nyunt, T.T., Sun, T.T., Krishnaswamy, M., Ying, L.H., Cho, C., Kyaw, N.B.B., Aung, W.Y.L. & Chanmuang N., C. (2020): Amber from Khamti, Sagaing Region, Myanmar. Journal of Gemmology, 37(3), 314-322.
Katha District Tigyaing Township (Htigyaing Township) ⓘ Tagaung Taung Ni deposit	[Opal] Harald Schillhammer collection

Namibia
Erongo Region Dâures Constituency ⓘ Tubussis Farm 22	[Opal-A var: Opal-AN] Schnaitmann, E. A., Nägele, H., Niedermayr, G., Brandstätter, F. & Jahn, S. (2007): Das Metazeunerit-Pocket auf Tubussis 22, Erongo. Mineralien-Welt 18 (2), 33-43. (in German)
Karibib Constituency ⓘ Erongo Mountains	[Opal-A var: Opal-AN] MinRec, Jan/Feb 2001
ⓘ Lattice quartz occurrence ('Gitterquarz-Fundstelle')	[Opal-A var: Opal-AN] E. Schnaitmann, F. Brandstätter, U. Kolitsch and G. Niedermayr (2008): Die „Gitterquarz“-Paragenese aus dem Erongo, Namibia. Mineralien-Welt 20 (1), 55-63.
Spitzkopje Area ⓘ Klein Spitzkopje granite stock (Kleine Spitzkoppe; Klein Spitzkoppe)	[Opal] Cairncross, B. (2005) Famous Mineral Localities: Klein Spitzkoppe, Namibia. Mineralogical Record 36(4) 317-335
Usakos ⓘ Ameib Farm 60	[Opal] No reference listed
Eureka Farm 99 ⓘ Eureka carbonatite	[Opal] Natural History Museum Vienna collection
Omaruru Constituency ⓘ Krantzberg Mine	[Opal] Jahn, S. & Bast, R. (2006): Der Krantzberg bei Omaruru, Namibia, und die Mineralvorkommen in seiner Umgebung. Mineralien-Welt 17 (3), 32-48.
Hardap Region ⓘ Rehoboth Rural	[Opal] von Bezing, L., Bode, R., and Jahn, S. (2008) Namibia Minerals and Localities. Edition Schloss Freudenstein, Bode Verlag GmbH, Haltern, pg 668 (in English)
Khomas Region Windhoek Rural Aris ⓘ Aris Quarries	[Opal] Wartha, R., Palfi, A., Niedermayr, G., Brandstätter, F. and Petersen, O. V. (2001): Der Aris-Phonolith-Komplex und seine Mineralien. In Bahmann, U. and A. (Eds.), Namibia – Zauberwelt edler Steine und Kristalle, Bode-Verlag, Haltern, Germany, pp. 172-179. (in German); Kolitsch, U., Blaß, G., Jahn, S., Cámara, F., von Bezing, L., Wartha, R. R., Tremmel, G., Sturla, M., Cerea, P., Skebo, M. and Ciriotti, M. E. (2016): Aris - mineralogy of the famous alkaline phonolite. AMI - Associazione Micromineralogica Italiana, Cremona, Italy, 95 pp.
Gamsberg area ⓘ Nauchas Farm 14	[Opal] Bezing, L. von, Bode, R. & Jahn, S. (2008): Namibia Minerals and Localities. Edition Schloss Freudenstein, Bode Verlag GmbH, Haltern, 668 pp. (in English)
Kunene Region ⓘ Khorixas	[Opal] Saphira Minerals specimens, Munich Show 2014
ⓘ Mesopotamia copper valley	[Opal] Gerhard Louw photo ID 983450
ǁKaras Region Karasburg West ⓘ Gaidip Farm 146	[Opal-A var: Opal-AN] Bezing, L. von, Bode, R. & Jahn, S. (2008): Namibia Minerals and Localities. Edition Schloss Freudenstein, Bode Verlag GmbH, Haltern, 386 pp. (in English)

Netherlands
Drenthe Borger-Odoorn Municipality ⓘ Hondsrug	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
Friesland ⓘ Ameland	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
ⓘ North Holland	[Amber] Gerard van der Veldt collection.
Overijssel ⓘ Borne Municipality	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
Hof van Twente Municipality ⓘ Delden	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
ⓘ Losser Municipality	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
Twenterand Municipality ⓘ Westerhaar-Vriezenveensewijk	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
South Holland ⓘ Noordwijk Municipality	[Amber] Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).

New Zealand
Auckland Region Lake Pupuke ⓘ Smales Quarry	[Opal-A var: Opal-AN] Rod Martin personal collection
ⓘ Rangitoto Island	[Opal-A var: Opal-AN] Collection of RJ Martin
Bay of Plenty Region ⓘ Calypso Vent field	[Opal] Schwarz-Schampera, U.,et al. (2007) Cruise Report SONNE 192/2, MANGO. Marine Geoscientific Research on Input and Output in the Tonga-Kermadec Subduction Zone
Kawerau District ⓘ Kawerau Geothermal field	[Opal] Milicich, S., Martin, R., and G. Bignall, 2007. Geothermal Well Cuttings and Core - an insight to below surface workings. 30th Annual Seminar of the Joint Mineralogical Societies of Australasia, Waihi Beach, New Zealand.
Mayor Island (Tuhua) ⓘ Omapu Bay (Western Bay)	[Opal] NZJGG, 2003, 46: 581-590. NZJGG, 1991, 34: 337-340. NZJGG, 1981, 24: 449-467
ⓘ Opo Bay (South East Bay)	[Opal] NZJGG, 2003, 46: 581-590. NZJGG, 1991, 34: 337-340. NZJGG, 1981, 24: 449-467
ⓘ Taratimi Bay (Crater Bay)	[Opal] Collection of RJ Martin
Rotorua District ⓘ Lake Rotorua Area	[Opal] Collection of RJ Martin
Mount Ngongotaha ⓘ Hendersons Quarry	[Opal] Tim Saunderson collection
Okataina ⓘ Mount Tarawera	[Opal] Collection of Rod Martin
ⓘ Te Kopia geothermal area	[Opal] Martin, R., Rodgers, K.A., Browne, P.R.L. (1999) The nature and significance of sulphate-rich, aluminous efflorescences from the Te Kopia geothermal field, Taupo Volcanic Zone, New Zealand. Mineralogical Magazine, June 1999, Vol. 63(3), 413-419.
ⓘ Waiotapu (Wai-O-Tapu)	[Opal] Jones, B., Renaut, R.W. (2006) Growth of siliceous spicules in acidic hot springs, Waiotapu geothermal area, North Island, New Zealand. Palaios: 21(5): 406-423.
ⓘ Frying Pan Lake	[Opal] Jones, B., Renaut, R. W., & Konhauser, K. O. (2005). Genesis of large siliceous stromatolites at Frying Pan Lake, Waimangu geothermal field, North Island, New Zealand. Sedimentology, 52(6), 1229-1252.
Canterbury Region Ashburton District ⓘ Gawler Downs	[Opal-A var: Opal-AN] Collection of RJ Martin
Christchurch City Banks Peninsula Lyttelton ⓘ Gollans Bay Quarry	[Opal] Collection of RJ Martin
Selwyn District Coalgate ⓘ Harper Hills Volcanics	[Opal] Collection of RJ Martin
ⓘ Rakaia Gorge	[Opal-A var: Opal-AN] Judy Rowe Collection
Waitaki District ⓘ Maerewhenua	[Opal-A var: Opal-AN] Judy Rowe collection
Hawke's Bay Region Central Hawke's Bay District ⓘ Blackhead Beach	[Opal] Nyman, S.L., Nelson, C.S., Campbell, K.A., Schellenberg, F., Pearson, M.J., Kamp, P.,Browne, G., King, P., 2006. Tubular carbonate concretions as hydrocarbon migration pathways?. In: Examples from North Island, New Zealand, New Zealand Petroleum Conference Proceedings. NZ Ministry of Economic Development, Auckland, NZ, p. 10.
Manawatu-Whanganui Region Ruapehu District Ohakune ⓘ Public works quarry (Ohakune scoria pit)	[Opal-A var: Opal-AN] Judy Rowe and Alfredo Petrov specimens
Tongariro National Park ⓘ Tongariro Alpine Crossing Northern Circuit	[Opal] Johnstone, R.D. (1979) Fumarole Incrustations and Some Aspects of the Thermal Alteration at Ketetahi, Mount Tongariro, New Zealand. Geothermal Institute, University of Auckland, New Zealand.
Marlborough Region Marlborough Sounds ⓘ D'Urville Island	[Opal-A var: Opal-AN] Collection of RJ Martin
New Zealand Outlying Islands Kermadec Islands ⓘ Brothers Volcano	[Opal] de Ronde, C.E.J.; Hannington, M.D.; Stoffers, P.; Wright, I.C.; Ditchburn, R.G.; Reyes, A.G.; Baker, E.T.; Massoth, G.J.; Lupton, J.E.; Walker, S.L.; Greene, R.R.; Soong, C.W.R.; Ishibashi, J.; Lebon, G.T.; Bray, C.J.; Resing, J.A. 2005 Evolution of a submarine magmatic-hydrothermal system : Brothers volcano, southern Kermadec arc, New Zealand. Economic geology, 100(6): 1097-1133; A. G. Reyes, C.E.J. DE Ronde, and C. W. R. Soong (2004) a Submarine Magmatic-hydrothermal System at Brothers Volcano, Kermadecs. Proceedings 26th NZ Geothermal Workshop pp 46-52
Northland Region Far North District Awanui ⓘ Gumdiggers Park	[Amber] http://www.gumdiggerspark.co.nz
Kaipara District ⓘ Tokatoka	[Opal] Mason, B. (1957): Larnite, scawtite, and hydrogrossular from Tokatoka, New Zealand. American Mineralogist 42, 379-392.
Whangarei District ⓘ Puhipuhi	[Opal] Collection of RJ Martin
ⓘ Mount Mitchell prospect	[Opal] Hampton, W.A., White, G.P., Hoskin, P.W.O., Browne, P.R.L., Rodgers , K.A. (2004) Cinnabar, livingstonite, stibnite and pyrite in Pliocene silica sinter from Northland, New Zealand. Mineralogical Magazine 68:1, 191-198.
ⓘ Rising Sun prospect	[Opal] Gary Leske specimen, 1984.
ⓘ Te Mata	[Opal] Aurora Minerals, 2005, PROSPECTING PERMIT 39 270 HAZELBROOK, NORTHLAND NEW ZEALAND ANNUAL REPORT, Ministry of Economic Development New Zealand Unpublished Petroleum Report MR4188
Otago Region Central Otago District Idaburn ⓘ Idaburn Mine	[Amber] Seyfullah, L.J., Sadowski, E-M, Schmidt, A.R. (2015) Species level determination of closely related arcucarian resins using FTIR spectroscopy and its implications for the provenance of New Zealand Amber, Department of Geobiology, University of Gottingen, Germany.
Roxburgh ⓘ Harliwich Mine (McPhersons)	[Amber] http://picssr.com/photos/otagorockandmineralclub/interesting/page12?nsid=90553334@no2
St. Bathans ⓘ Cambrians (Welshmans Gully; Four Mile)	[Amber] Dunstan Times newspaper (1875) Mining Items, issue 671, 26 February 1875.
Dunedin City ⓘ Doctors Point	[Opal-A var: Opal-AN] Judy Rowe Collection
Otago Peninsula Portobello ⓘ Portobello Bay	[Opal] Collection of RJ Martin (initial ID by S Courtney, Univ of Auck)
ⓘ Taiaroa Head	[Opal] Collection of RJ Martin
Waitaki District ⓘ Bridge Point	[Opal] Collection of RJ Martin
ⓘ Duntroon	[Opal-A var: Opal-AN] Knut Edvard Larsen collection # MM- 3930 (collected by Dick Dufton)
ⓘ Moeraki Point	[Opal] Collection of RJ Martin (initial ID by S Courtney, Univ of Auck)
Oamaru ⓘ Old Mill Road Quarry (Dog Pound Quarry)	[Opal-A var: Opal-AN] Old Mill or Dog Pound Quarry, Oamaru, Essence of Micro-Scope (NZ), Auton and Thornton
Southland Region Gore District Waimumu ⓘ New Vale Mine (Goodwin Coal Mine)	[Amber] Ferguson, D.K., Lee, D.E., Bannister, J.M., Zetter, R., Jordon, G.J., Vavra, N., Mildenhall, D.C. (2009) The taphonomy of a remarkable leaf bed assemblage from the Late Oligocene-Early Miocene Gore Lignite Measures southern New Zealand, International Journal of Coal Geology.
Southland District ⓘ Round Hill	[Amber] Craw, D., Kerr, G., Reith, F., Falconer, D. (2015) Pleistocene paleodrainage and placer gold redistribution western Southland New Zealand, New Zealand Journal of Geology and Geophysics, 58:2, 137-153.
Taranaki Region Stratford District Egmont National Park ⓘ York Road Quarry	[Opal] Collection of RJ Martin
Tasman Region Takaka ⓘ Copperstain Creek	[Opal] Collection of RJ Martin
Waikato Region Hauraki District Karangahake ⓘ Rahu prospect	[Opal] Zuquim, M. de P.S, Mauk, J.L., Rowland, J.V., Atkinson, P., Stevens, M. (2012) Structural controls on the Rahu prospect, Hauraki Goldfield. Proceedings of the 2012 annual conference, New Zealand Branch of the Australasian Institute of Mining and Metallurgy, pp 281-290.
Taupo District Atiamuri ⓘ Ongaroto Road	[Opal] Collection of Rod Martin
ⓘ Broadlands (Ohaaki)	[Opal] Milicich, S., Martin, R., and G. Bignall, 2007. Geothermal Well Cuttings and Core - an insight to below surface workings. 30th Annual Seminar of the Joint Mineralogical Societies of Australasia, Waihi Beach, New Zealand.
ⓘ Lake Taupo	[Opal] Brathwaite, R. L., & Rae, A. J. (2021). Epithermal Zeolite Alteration Associated with Siliceous Sinters, Hydrothermal Eruption Breccias, and Gold-Silver Mineralization, Central Taupo Volcanic Zone, New Zealand. Economic Geology, 116(5), 1093-1114.
ⓘ Rangatira Point (Ponui Point)	[Opal] Collection of RJ Martin
Orakeikorako Thermal Area (Orakei Korako; The Hidden Valley) ⓘ Ruatapu Cave (Alum Cave)	[Opal] Rod Martin, Minerals of Ruatapu Cave, Orakei Korako, Taupo Volcanic Zone. Essence of Microscope (NZ)
Wairakei ⓘ Lake Rotokawa	[Opal-A var: Opal-AN] Rod Martin personal collection
ⓘ Ngatamariki thermal area (Pavlova Spring)	[Opal-A var: Opal-AN] Brotheridge, J.M.A., Browne, P.R.L., Hochstein, M.P. (1995) The Ngatamariki geothermal field New Zealand: surface manifestations - past and present in Proceedings of the 17th New Zealand Geothermal Workshop 1995. Presented by the Geothermal Institute, The university of Auckland in conjunction with The Centre for Continuing Education. p61.
ⓘ Wairakei geothermal area (Craters of the Moon)	[Opal] Tschernich, R. (1992) Zeolites of the World, Geoscience Press, Inc.
Thames-Coromandel District Hikuai ⓘ Broken Hills Mine	[Opal] Moore, C.R. (1979) Geology and mineralisation of the former Broken Hills gold mine, Hikuai, Coromandel, New Zealand. New Zealand Journal of Geology and Geophysics, 22:3, 339-351.
ⓘ Puketui Road mordenite locality	[Opal-A var: Opal-AN] Collection of RJ Martin
Tairua River ⓘ 4th Branch	[Opal-A var: Opal-AN] Collection of RJ Martin
ⓘ Kauaeranga Valley	[Opal] Collection of RJ Martin
ⓘ Tairua	[Opal] L. D. Swindale & I. R. Hughes (1968) Hydrothermal association of pyrophyllite, kaolinite, diaspore, dickite, and quartz in the Coromandel Area, New Zealand, New Zealand Journal of Geology and Geophysics, 11:5, 1163-1183,
ⓘ Tairua opal mine	[Opal] Collection of RJ Martin
Wellington Region South Wairarapa District Red Hill ⓘ Volcano Road Quarry	[Opal] CF Johnson collection; Collected by CF Johnson

North Macedonia
Cheshinovo-Obleshevo Municipality ⓘ Spanchevo	[Opal] opal https://www.mindat.org/photo-1297356.html
Lipkovo Municipality ⓘ Lojane	[Opal] Hiessleitner, G. (1931): Geologie mazedonischer Chromeisenlagerstätten. Berg- und Hüttenmännisches Jahrbuch der Montanistischen Hochschule in Leoben, 79, 47-57.
Probistip Municipality Kratovo-Zletovo ore district ⓘ Plavica deposit (Plavica-Zlatica deposit; Plavitsa deposit)	[Opal] Serafimovski, T., Zlatkov, G., & Tasev, G. (2015). Calculation of variation and ore-bearing coefficients in the Plavica epithermal polymetallic deposit, Eastern Macedonia. 15th International Multidisciplinary Scientific Geoconference SGEM 2015, 3, 119-127.
ⓘ Zletovska Reka Mine	[Opal] Radusinovic, D. (1974). Zletovska Reka uranium deposit. In IAEA Symposium on the formation of uranium ore deposits. Athens, Greece (pp. 593-601).
ⓘ Plesenci	[Opal] Serafimovski, Todor and Tasev, Goran and Gjorgjiev, Lazar (2015) Sulfur isotope composition in the Plesenci native sulfur mineral deposit, Republic of Macedonia. Earth and Planetary Science, 13. pp. 35-38. ISSN 1878-5220
Veles Municipality ⓘ Groot	[Opal] Spasovski, O, Doneva B. (2009) Metalogenetic Characteristics of the Groot Fe-Ni Deposit Republic of Macedonia. 3rd Balkan Mining Congress, BALKANMINE 2009. :23.: The Chamber of Mining Engineers of Turkey
ⓘ Groot Fe-Ni Deposit	[Opal] Spasovski, O, Doneva B. (2009) Metalogenetic Characteristics of the Groot Fe-Ni Deposit Republic of Macedonia, 3rd Balkan Mining Congress, BALKANMINE 2009: 23: The Chamber of Mining Engineers of Turkey.

Norway
Agder Iveland Frikstad ⓘ Frikstad 07 Feldspar Quarry	[Opal-A var: Opal-AN] Revheim, O. (2004): Gadolinitt-(Y) og andre mineraler fra Slobrekka. Norsk Bergverksmuseum Skrift 28: 43-50
Nordland Hamarøy Finnøya ⓘ Håkonhals Quarry	[Opal] Husdal, T. (2008): The minerals of the pegmatites within the Tysfjord granite, northern Norway. Norsk Bergverksmuseum, skrift 38, 5-28.
Oslo Grorud Bånkall ⓘ Kristiansen Quarry (Bånkall Quarry)	[Opal] Kvamsdal, L.O. (1998): Mineralene fra Nordmarkitt og Grefsensyenitt i Oslofeltet. AS Merkur-Trykk, Oslo. 72p
ⓘ Huken Quarry	[Opal] Kvamsdal, L. O. (1999): Mineralene fra Huken pukkverk i Oslo. STEIN 26 (4), 14-47
Trøndelag Oppdal ⓘ Åmotsdalen	[Opal-A var: Opal-AN] Witsø, T. (1995): Mineraler i Oppdal med beskrivelse. Driva Kro og steinsenter. Unpublished paper. http://vinstradalen.no/pdf/Mineraler.pdf
ⓘ Bjørnåa	[Opal-A var: Opal-AN] http://www.strahlen.org/vp/no/bjornaa/
ⓘ Northwest of Snøhetta Mountain	[Opal-A var: Opal-AN] Witsø, T. (1995): Mineraler i Oppdal med beskrivelse. Driva Kro og steinsenter. Unpublished paper. http://vinstradalen.no/pdf/Mineraler.pdf
Trollheimen ⓘ Gjevilvassdalen	[Opal-A var: Opal-AN] Witsø, T. (1995): Mineraler i Oppdal med beskrivelse. Driva Kro og Steinsenter. Unpublished paper. http://vinstradalen.no/pdf/Mineraler.pdf; Witsø, T. (1995): Mineraler i Oppdal med beskrivelse. Driva Kro og steinsenter. Unpublished paper. http://vinstradalen.no/pdf/Mineraler.pdf
Vestfold og Telemark Drangedal Tørdal ⓘ Heftetjern pegmatite	[Opal] Raade, G. & Kristiansen, R. (2000a): Mineralogy and geochemistry of the Heftetjern granite pegmatite, Tørdal: a progress report. Norsk Bergverksmuseum Skrifter. 17, 19-25
Holmestrand Fjordveien ⓘ Railway tunnel	[Opal-A var: Opal-AN] Nordrum, F.S. (2012): Noen funn av mineraler i Norge 2011-2012. Norsk Bergverksmuseum Skrifter. 49, 117-124
ⓘ Kjeksrød	[Opal] L. O. Kvamsdal (1998): Mineralene fra Nordmarkitt og Grefsensyenitt i Oslofeltet. AS Merkur-Trykk, Oslo (in Norwegian), p. 24.
ⓘ Løkenåsen	[Opal-A var: Opal-AN] Nordrum, F.S., Larsen, S. Bergstrøm, T & Larsen, A.O. (1997): Mineralfunn langs ny E 18 i Drammen og Nordre Vestfold. STEIN 24 (3), 102-110
Sande Selvik ⓘ Nordre Jarlsberg Brygge	[Opal-A var: Opal-AN] Nordrum, F.S. (2012): Noen funn av mineraler i Norge 2011-2012. Norsk Bergverksmuseum Skrifter. 49, 117-124
ⓘ Skafjellås	[Opal] Knut Eldjarn collection
Kragerø Valberg ⓘ Valberg Quarry	[Opal] Peter Andresen observation oct.2003
Larvik Brunlanes ⓘ Nalum	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1991.
ⓘ Thorstein Quarry	[Opal-A var: Opal-AN] Svein A. Berge collection 1992
Hedrum ⓘ Farmenrøysa	[Opal-A var: Opal-AN] Larsen, K. E. & Andersen, F. (2009): Mineralforekomster i den østlige delen av Siljan-Hvarnes plutonkompleks, sørvestre Vestfold. Norsk Bergverksmuseums Skrift, 41: 54-63
Lågendalen ⓘ Bratthagen 3 hillside pegmatites	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1989.
Lysebo ⓘ Lysebo roadcut	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1992.
Langesundsfjorden Store Arøya (Arøy) ⓘ Paradisbukta	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1993.
Malerød ⓘ Vardåsen Quarry	[Opal] Andersen, F., Berge, S.A. & Burvald, I. (1996): Die Mineralien des Langesundsfjords und des umgebenden Larvikit-Gebietes, Oslo-Region, Norwegen. Mineralien-Welt 7(4), 21-100
Pauler ⓘ Roadcut 1	[Opal] Field observarions by Peter Andresen, 2010.
ⓘ Stavern (Fredriksvärn)	[Opal] Fredholm, K. A. (1874). Opal från zirkonsyeniten vid Fredriksvœrn i Norge. Geologiska Föreningen i Stockholm Förhandlingar, 2(4), 131–131.; Brøgger, W.C. (1890): Die Mineralien der Syenitpegmatitgänge der südnorwegischen Augit-und Nephelinsyenite. Zeitschrift für Kristallographie und Mineral.16. p.15
Jahren pegmatite (Jaren pegmatite) ⓘ Jahrehagen cottage grounds	[Opal-A var: Opal-AN] Andresen, P., Friis, H., Kjærnet, T. & Larsen, A.O. (2018): The minerals of the Jahren pegmatite, one of the major pegmatites in the Larvik Plutonic Complex. Norsk Mineralsymposium 2018: 5-22.
ⓘ Jahren Feldspar Quarry (Jaren Feldspar Quarry)	[Opal-A var: Opal-AN] Atle Michalsen collection, photo-id 1212051
Tvedalen ⓘ Tuften	[Opal] Engvoldsen,T.,Andersen, F.,Berge, S.A. & Burvald, I. (1991): Pegmatittmineraler fra Larvik ringkompleks. STEIN 18(1),15-71
ⓘ A/S Granit Quarry	[Opal] Larsen, A. O. (ed.) (2010): The Langesundsfjord. History, geology, pegmatites, minerals. Bode Verlag Gmbh, Salzhemmendorf, Germany, 240 pp.
Porsgrunn Eidanger Bergsbygda ⓘ Gurpekollen	[Opal] Svein A.Berge observation on collected materiale august 2012
Langesundsfjorden Siktesøya ⓘ Brønnebukta	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1990.
Sandefjord Fokserød ⓘ Aasmund Berg Quarries	[Opal] Engvoldsen, T., Andersen, F., Berge, S. A. & Burvald, I. (1991): Pegmatittmineraler fra Larvik ringkompleks. STEIN 18(1):15-71
ⓘ Hotvedt Quarry	[Opal] Berge, S. A. & Larsen, A. O. (1980): Mineraler fra Sandefjordsområdet-IV. Granater. NAGS-nytt 7 (2): 21-24
Haneholmveien ⓘ Virikkollen	[Opal-A var: Opal-AN] Larsen, K. E. & Kolitsch, U. (2012): An unique mineral suite in a syenite pegmatite at Virikkollen, Sandefjord, Larvik Plutonic Complex, Norway. Norsk Bergverksmuseum Skrifter. 49, 35-44
Østerøya ⓘ Bergan	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1992.
ⓘ Eian	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1991.
Yxney ⓘ Kjela	[Opal-A var: Opal-AN] Svein A. Berge collection/observation 1993.
Råstad ⓘ Nordre Bergan	[Opal] Engvoldsen,T.,Andersen, F.,Berge, S.A. & Burvald, I. (1991): Pegmatittmineraler fra Larvik ringkompleks. STEIN 18(1),15-71
Vesterøya ⓘ Buer	[Opal] Berge, S.A., Larsen, K.E. & Andersen, F. (2011): Buer, Vesterøya, Sandefjord- en typelokalitet for et nytt mineral. Norsk Bergverksmuseum Skrift. 46: 49-56
ⓘ Husebyåsen prospect	[Opal] Berge, S. A. (2013):Mineralene i Husebyyåsen feltspatbrudd, Vesterøya, Sandefjord. Norsk Bergverksmuseum Skrifter. 50, 93-99
ⓘ Kamfjord Quarry	[Opal] Engvoldsen,T., Andersen, F., Berge, S. A. & Burvald, I. (1991): Pegmatittmineraler fra Larvik ringkompleks. STEIN 18 (1),15-71
Skien ⓘ Flekkeren	[Opal] Jamtveit, B., Dahlgren, S., Austrheim, H. (1997) High-grade contact metamorphism of calcareous rocks from the Oslo Rift, Southern Norway. American Mineralogist: 82: 1241-1254.
Tønsberg Ramnes ⓘ Himberg Quarry	[Opal] Andersen, F. & Berge, S. A. (1994): Himberg pukkverk, Ramnes, Vestfold. STEIN 21 (2), 96-102
Vestland Sunnfjord Jølster ⓘ Jølstravatnet	[Opal] Larsen, K.E. & Nordrum, F.S. (2013): Noen funn av mineraler i Norge 2012-2013. Norsk Bergverksmuseum Skrift. 50, 111-117
Ullensvang Hardangervidda West ⓘ Ringedalsvann area	[Opal] Nordrum, F. S. (2015): Anatas und weitere Mineralien aus der westlichen Hardangervidda, Norwegen. Mineralien-Welt. 26(6), 56-85
Viken Asker ⓘ Borgenåsen	[Opal] Knut Eldjarn collection
ⓘ Heggedalsveien	[Opal] Stensrud, S. (2004): Mineralfunn i ny sikkerhetstunnel i Vardåsen og langs ny gangvei langs Heggedalsveien i Asker i 2002-2003. Norsk Bergverksmuseum Skrift 28: 76-102
Hurum ⓘ Fuglemyr	[Opal-A var: Opal-AN] Knut Edvard Larsen MM-collection (#1089)
ⓘ Vardåsen Tunnel	[Opal] Stensrud, S. (2004): Mineralfunn i ny sikkerhetstunnel i Vardåsen og langs ny gangvei langs Heggedalsveien i Asker i 2002-2003. Norsk Bergverksmuseum Skrift 28: 76-102
Drammen Drammensmarka ⓘ Myrseter area	[Opal] Berg, H.-J. (198?): Myrseter-Landfall. Turguide. (unpublished collectors guide)
ⓘ Hans-Jørgens locality	[Opal] Knut Edvard Larsen collection and observation mai 2018
ⓘ E 134 Road	[Opal-A var: Opal-AN] Nordli, Ø. (1997): Ny E 134 Drammen- Nedre Eiker. Mineraler fra veiutbyggingen. STEIN 24 (3), 116-121
Nedre Eiker Nedre Eiker Church ⓘ Batteriet	[Opal] Raade, G. (1969): Contribution to the Mineralogy of Norway, No 40. Cavity minerals from the permian biotite granite at Nedre Eiker Church. Norsk Geologisk Tidskrift 49, 227-239.
Svelvik ⓘ Brentåsen	[Opal-A var: Opal-AN] Larsen, S. & Bergtsrøm, T. (2004): Svelvik- Topas. STEIN 31(4), 11
ⓘ Juve Quarry	[Opal-A var: Opal-AN] Nordrum, F.S. (2007): Nyfunn av mineraler i Norge 2006-2007. STEIN 34 (2): p.15-16
Eidsvoll Minnesund ⓘ Byrud Emerald Mines	[Opal] Kvamsdal, L.O., Eldjarn, K. (2006): Mineralene i smaragdgruvene ved Byrud gård, Minnesund, Norge. STEIN 33 (4), 4-20
Lier Drammensmarka ⓘ Sauesetra	[Opal] Nordrum, F.S. & Larsen, A.O.(1999): Einige neue Mineralfunde aus dem Gebiet Drammen-Holmestrand in Norwegen. MineralienWelt 10 (6):57-61
Lunner ⓘ Gjerdingselva	[Opal] Raade, G. & Haug, J.(1982): Gjerdingen. Fundstelle seltener Mineralien in Norwegen. LAPIS 7, 9-15
Øståsen ⓘ Midtmoen	[Opal] Kvamsdal, L.O. (1993): Noen mineraler fra nordmarkitten mellom Roa og Maura. STEIN 20 (1), 30-45
Nittedal ⓘ Delebekken Quarry	[Opal] Kvamsdal, L.O. (2018) Delebekken - en ny elpidittlokalitet i Nordmarka ved Oslo. Norsk Mineralsymposium 2018: 29-43
ⓘ Gjelleråsen	[Opal] L. O. Kvamsdal (1998): Mineralene fra Nordmarkitt og Grefsensyenitt i Oslofeltet. AS Merkur-Trykk, Oslo(in Norwegian), p. 22.

Oman
ⓘ Muscat Governorate	[Opal]

Pacific Ocean
East Pacific Rise ⓘ EPR 13° N	[Opal] Econ Geol (1985) 80:221-249
Sea of Japan Honshu Island borderland ⓘ Sado ridge	[Opal] Markov, Y.D., Mozherovskii, A.V., Derkachev, A.N., Barinov, N.N., and Sereda, N.A. (2002): Lithology and Mineral Resources 37(2), 121-129.
South California Borderland ⓘ Hoss Seamount	[Opal] Hein, J.R., Reid, J.A., Conrad, T.A., Dunham, R.E., Clague, D.A., Schulz, M.S., and Davis, A.S. (2010): USGS Open-File Report 10-1069
Tonga-Kermadec Arc ⓘ Volcano No. 19	[Opal] Schwarz-Schampera, U.,et al. (2007) Cruise Report SONNE 192/2, MANGO. Marine Geoscientific Research on Input and Output in the Tonga-Kermadec Subduction Zone
Woodlark Basin ⓘ Franklin Seamount	[Opal] Mozgova, N.N., Borodaev, Yu.S., Efimov, A.V., Sandomirskaya, S.M., Nenasheva, S.N., Lisitsyn, A.P., Bogdanov, Y.A., Murav'ev, K.G. (1993): Silver minerals in oceanic hydrothermal ore occurrences (Manus and Woodlark basins, Papua New Guinea region). Geol. Ore Deposits: 35(4)" 297-306 (transl. from Geol. Rudnyk Mestorozhdenii: 35: 333-343); in: Jambor, J.L., Puziewicz, J., and Roberts, A.C. (1995): New mineral names. American Mineralogist: 80: 1331

Pakistan
Gilgit-Baltistan Roundu District Haramosh Mts. ⓘ Stak Nala	[Opal-A var: Opal-AN] Jose Zendrera specimen
ⓘ Rondu	[Opal] José Zendrera collection
Shigar District Braldu Valley Nyet ⓘ Nyet Bruk	[Opal] Ikram Mineralogy
ⓘ Skardu Area	[Opal-A var: Opal-AN] imported from Rondu District

Panama
Veraguas Province ⓘ Santa Rosa Au Mine	[Opal] Byington, C.B. and Russell, M.R., 2001, Economic geology and ore controls of the Santa Rosa Mine – An integrated structural analysis approach, Canazas, Veraguas, Republic of Panama: Society of Economic Geologists Special Publication 8, p. 318-329.

Papua New Guinea
Bismarck Sea ⓘ Manus Basin	[Opal] New Data on Minerals (2004): 39: 91-98
ⓘ Bikpela Binatang (Bikpela)	[Opal] Binns, R. A. (2014). Bikpela: A large siliceous chimney from the PACMANUS hydrothermal field, Manus basin, Papua New Guinea. Economic Geology, 109(8), 2243-2259.
ⓘ PACMANUS hydrothermal field	[Opal] Zhigang Zeng, Shuai Chen and Xiaoyuan Wang. 2012 Mineralogical and micromorphological characteristics of Si-Fe-Mn oxyhydroxides from the PACMANUS hydrothermal field, Eastern Manus Basin. Science China Earth Science 55(12)
Milne Bay Province D'Entrecasteaux Islands Fergusson Island (Moratau) ⓘ Iamalele prospect (Airstrip prospect)	[Opal] Province, M. B., & Guinea, P. N. (2004). Technical Report On The Fergusson Property.
ⓘ Wiyoumaga Prospect	[Opal] Province, M. B., & Guinea, P. N. (2004). Technical Report On The Fergusson Property.
Morobe Province ⓘ Wau Mine	[Opal] Econ Geol (1984) 79:638-655
New Ireland Province Lihir Island Luise Stratovolcano ⓘ Ladolam Gold deposit (Lihir Mine)	[Opal] http://www.portergeo.com.au/tours/pacificgold99/pg99m1.asp#lihir

Paraguay
Central Department Asuncion ⓘ Botanical Garden	[Opal] Alfredo Petrov field observations, 1989.

Peru
Amazonas ⓘ Santiago river Amber occurrence	[Amber] J. Hyrsl (2012) Gemstones of Peru, p. 33
Arequipa Caravelí Province ⓘ Acarí District	[Opal] J.Hyrsl (2012) Gemstones of Peru, p. 56
ⓘ Acari Mine	[Opal] Hyrsl & Rosales (2003), Min. Record 34:254
Ayacucho Lucanas Province Saisa District ⓘ Saisa	[Opal] J.Hyrsl (2012) Gemstones of Peru, p. 57
Cajamarca Cajamarca Province ⓘ Cajamarca District	[Opal] Rob Lavinsky specimen
ⓘ El Sol 3 deposit (Encajon)	[Opal] Dill, H.G., Bosse, H.-R., Henning, K.-H., Fricke, A., and Ahrendt, H. (1997): Mineralium Deposita 32, 149-163.
Ica Ica Province Ica District ⓘ Monte Rosa Mine	[Opal-A var: Opal-AN] Extra Lapis - English No. 10 Opal
Pisco Province Humay District ⓘ Lily Mine	[Opal]
ⓘ Pisco District	[Opal] J.Hyrsl (2012) Gemstones of Peru, p. 57
Puno Titicaca Lake ⓘ Amantani Island	[Opal] Jacques Valverde self collecting (summer 2007); Jacques Valverde self collecting (summer 2007)

Poland
Lower Silesian Voivodeship Dzierżoniów County Gmina Niemcza Niemcza ⓘ Pangelberg	[Opal] Tietze O. (1916) - Heulandit am Pangelberg bei Nimptsch; Jahrbuch der Königlich Preussischen Geologischen Landesanstalt für 1915, Band 36, Teil I, Heft 2. Seite 398-400 mit 1 Kristallfigur im Text.
Jawor County Gmina Męcinka ⓘ "Bartnica" mine (Brachów)	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
ⓘ Słup	[Opal] Jäkel [F.W.?] (1853) - Ueber die in der Umgegend von Liegnitz vorkommenden Mineralien und ihre technische Anwendung. Jahres-Bericht der Schlesischen Gesellschaft für Vaterländische Cultur Breslau. P.51-61
Jelenia Góra ⓘ Sobieszów	[Amber] Traube, H. (1888) Die Minerale Schlesiens [The Minerals of Silesia]. J.U. Kern's Verlag, Breslau, 286 pages [in German].
Kamienna Góra County Kamienna Góra ⓘ Mount Bukowina	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Kłodzko County Gmina Nowa Ruda ⓘ Świerki	[Opal] Heflik W., Pawlikowski M., Sobczak T., Sobczak N (1993) Jaspers from Swierki near Now a Ruda, Lower Silesia, Poland. Journal of Gemmolog y 23 (6): 356-359.
ⓘ Świerki melaphyre quarry	[Opal] Heflik W., Pawlikowski M., Sobczak T., Sobczak N (1993) Jaspers from Swierki near Now a Ruda, Lower Silesia, Poland. Journal of Gemmolog y 23 (6): 356-359.
Gmina Stronie Śląskie Kletno ⓘ Żmijowiec	[Opal] Gil, G.; Gunia, P.; Barnes, J.D.; Szymański, M.; Jokubauskas, P.; Kalbarczyk-Gil, A.; Bagiński, B. (2020) Origin of Talc and Fe-Ti-V Mineralization in the Kletno Deposit (the Śnieżnik Massif, SW Poland). Minerals 10, 13.
Legnica County Gmina Legnickie Pole Lubień ⓘ Lubień quarry	[Opal] Krzysztof Andrzejewski
Lubań County Gmina Leśna Grabiszyce Średnie ⓘ Grodziszcze Mtn.	[Amber] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Lwówek Śląski County Gmina Lubomierz Chmieleń ⓘ Chmieleń basalt quarry	[Opal] Weigel J.A.V. (1800) Geographische, naturhistorische und technologische Beschreibung des souverainen Herzogthums Schlesien. Das Fürsterthum Jauer. Zweiter Theil · Volume 2 Leopold von Buch 1802 - Geognostische Beobachtungen auf Reisen durch Deutschland und Italien. I. Entwurf einer geognostischen Beschreibung von Schlesien ; In Leopold von Buch's Gesammelte Schriften 1867 Erster Band. Bei Haude und Spener, Berlin Kaluza A. 1818 - Übersicht der Mineralien Schlesiens und Glatz nebst ihren Fundörtern und vielen neuen Höhenmessungen auf 4 Karten dargestellt. Gedruckt bei Kreuzer und Scholz. Breslau
Gmina Lwówek Śląski Płóczki Górne ⓘ Lipień Hill	[Opal] Weigel J.A.V. (1800) Geographische, naturhistorische und technologische Beschreibung des souverainen Herzogthums Schlesien. Das Fürsterthum Jauer. Zweiter Theil · Volume 2
Gmina Mirsk Proszowa ⓘ Urwista basalt quarry	[Opal] Adamczyk Z. (2008) Ewolucja wulkanizmu kenozoicznego Przedgórza Rębiszowskiego (Dolny Śląsk)
Strzelin County Gmina Przeworno Krzywina ⓘ Jegłowa quarry	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Przeworno ⓘ Przeworno marble quarry	[Opal] Schumacher K. (1878) Die Gebirgsgruppe des Rummelberges bei Strehlen. Zeitschrift Deutsche Geologische Gesellschaft. Bd. 30. Berlin (In German) Schumacher K. (1878) Über die Kalklager der Strehlener Gegend. Inaugural-Dissertation Welche mit Genehmigung der Philosophischen Facultät der Königl. Universität Breslau zur Erlangung der Doctorwürde Mittwoch den 7. August 1878 Vormittags 11 Uhr in der Aula Leopoldina - Breslau (In German)
Gmina Strzelin ⓘ Gębczyce skarn quarry	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Świdnica County Gmina Marcinowice Wirki ⓘ 'Wiry' magnesite mine	[Opal] Harańczyk C., Prochazka K. (1974) Uwodnione krzemiany magnezowo-niklowe z Wir na Dolnym Śląsku. Prace Muzeum Ziemi nr 22 (In Polish)
Gmina Strzegom Jaroszów ⓘ Jaroszów clay pit	[Amber] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Strzegom ⓘ Szeroka quarry	[Opal] - Glocker E.F. (1829) - Über den schlesischen Hyalith, besonders über einige neu entdeckte Formen desselben, sowie über dessen Vorkommen und Entstehung Nova Acta Physico-Medica Bd.14 - Lasaulx A. v. (1876) - Über ein Hyalith-Vorkommen am Breitenberg bei Striegau. Neues Jahrbuch für Mineralogie
Gmina Świdnica ⓘ Bystrzyca Górna	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Wałbrzych ⓘ Biały Kamień	[Amber] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish]
Wałbrzych County Jedlina-Zdrój ⓘ Jedlinka	[Amber] Traube, H. (1888) Die Minerale Schlesiens [The Minerals of Silesia]. J.U. Kern's Verlag, Breslau, 286 pages [in German].
Wrocław City ⓘ Kleczków	[Amber] Traube, H. (1888) Die Minerale Schlesiens [The Minerals of Silesia]. J.U. Kern's Verlag, Breslau, 286 pages [in German].
Wrocław County Gmina Jordanów Śląski ⓘ Jordanów nephrite quarry	[Opal-A var: Opal-AN] Szełęg, E., Galuskina, I. 2010: Mineralogy of Lower Silesia, Poland. Acta Mineralogica-Petrographica, Field Guide Series, Vol. 17, 1–15.
Gmina Sobótka Nasławice ⓘ Serpentinite quarry	[Opal-A var: Opal-AN] DUBIŃSKA E., 1995: Rodingites of the eastern part of Jordanów-Gogołów serpentynite massif, Lower Silesia, Poland. Can. Mineral., 33, 585-608.GALUSKIN E., SZEŁĘG E., 2003: The first finding of Ag-amalgamates in rodingites (Nasławice, Lower Silesia, Poland). Mineralogical Society of Poland - Special Papers, Vol. 22.
Ząbkowice Śląskie County Gmina Bardo ⓘ Grochowa	[Opal] Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
Gmina Ciepłowody ⓘ Koźmice	[Opal] Traube, H. (1888) Die Minerale Schlesiens. J.U. Kern's Verlag, Breslau, 286 pages [in German].
ⓘ Koźmickie Wzgórze - Mühlberg	[Opal] Lehmann J.G. (1755) Histoire du Chrysoprase de Kozemitz. Histoire de l'Académie Royale des Sciences et des Belles-Lettres de Berlin P. 202-214 (In French)
ⓘ Gmina Ząbkowice Śląskie	[Opal] Michael W. Kieron collection
ⓘ Braszowice	[Opal] Alfredo Petrov specimen Lis, J., Sylwestrzak, H. (1986) Minerały Dolnego Śląska [Minerals of the Lower Silesia]. Wydawnictwa Geologiczne, Warszawa, 791 pages [in Polish].
ⓘ Szklary	[Opal] Spangenberg, K., and Müller, M. (1949): Contributions to Mineralogy and Petrology 1(5/6), 560-572.
ⓘ Szklary Chrysoprase Mine	[Opal] Spangenberg, K., and Müller, M. (1949): Die lateritische Zersetzung des Peridotits bei der Bildung der Nickelerzlagerstätte von Frankenstein in Schlesien. Contributions to Mineralogy and Petrology 1(5/6), 560-572
ⓘ Szklary nickel deposit	[Opal] University of Adelaide, South Australia - Tate Museum collection # 22847. Ex. O.W Flörke Collection Kaczan, W., Kudełko, J., Wirth, H. (2021) Szklary nickel deposit — a review and introduction to attempts in hydrometallurgical processing. Mineral Economics, 34, 315-322.
Złotoryja County Gmina Świerzawa Nowy Kościół ⓘ Jeziorna quarry	[Opal] Kuhn, B., Zimmermann, E. (1918) Erläuterungen zur geologische Karte von Preussen und benachbarten Deutschen Ländern. Blatt Schönau an der Katzbach. Lieferung 202. Königlich-Preussische Geologische Landesanstalt, Berlin.
Gmina Zagrodno Grodziec ⓘ Grodziec basalt	[Opal] Trippke, P. (1878) Über den Enstatit aus den Olivinknollen des Groditzberges. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie. pp. 681-698.
Lublin Voivodeship Lubartów County ⓘ Górka Lubartowska amber deposit	[Amber] Państwowy Instytut Geologiczny (PIG)
Parczew County ⓘ Siemień amber deposit	[Amber] Woźny E. 1967 — Występowanie numulitów w bartonie z Siemienia koło Parczewa. Przegląd Geologiczny, 15: P.419–420 (In Polish)
Opole Voivodeship Namysłów County ⓘ Gmina Namysłów	[Amber] Traube, H. (1888) Die Minerale Schlesiens [The Minerals of Silesia]. J.U. Kern's Verlag, Breslau, 286 pages [in German].
ⓘ Opole City County	[Opal var: Hyalite] Roemer, C.F. (1870) Geologie von Oberschlesien: Erläuterungen + 50 Tafeln [Geology of Upper Silesia: Explanations + 50 panels]. Druck von R. Nischkowsky, Breslau, 587 pages.
ⓘ Groszowice quarry	[Opal] Traube, H. (1888) Die Minerale Schlesiens. J.U. Kern's Verlag, Breslau, 286 pages [in German].
Pomeranian Voivodeship ⓘ Gdansk City	[Amber] Flamini A., Graziani G., Grubessi O. (1974) - Inclusi di solfuro di ferro nelle ambre baltiche. Periodico di mineralogia – Roma, pp. 331-338 [www.johnbetts-fineminerals.com]
Silesian Voivodeship Bytom Bobrek ⓘ Bobrek heap	[Opal] Kruszewski, Ł. (2018)(?): Geochemical Behavior of Trace Elements in Upper and Lower Silesian Basin Coal-Fire Gob Piles, Poland. Coal and Peat Fires, vol. 5, xx-xx (in review/correction); Ł. Kruszewski EPMA/PXRD data
Wodzisław County Radlin ⓘ Marcel mine heap	[Opal] Kruszewski, Ł., Fabiańska, M.J., Segit, T., Kusy, D., Motyliński, R., Ciesielczuk, J., Deput, E., (2019): Carbon-nitrogen compounds, alcohols, mercaptans, monoterpenes, acetates, aldehydes, ketones, SF6, PH3, and other fire gases in coal-mining waste heaps of Upper Silesian Coal Basin (Poland) – a re-investigation by means of in situ FTIR external database approach. Science of The Total Environment (in press)
Subcarpathian Voivodeship Rzeszów County Gmina Błażowa ⓘ Futoma	[Opal] Personally collected by Zając Piotr in 2013

Portugal
Aveiro Albergaria-a-Velha Branca ⓘ Palhal Mine	[Opal-A var: Opal-AN] Marques de Sá, J. & Leal Gomes, C. (2010): Les mines de cuivre et nickel de Palhal et Telhadela, Albergaria-a-Velha, Aveiro, Portugal. Le Règne Minéral, 92, 36-47.
Azores ⓘ São Miguel	[Opal] Museu Nacional de História Natural e da Ciência, Lisboa, colecção António Bello.
ⓘ Água de Pau Volcano	[Opal] Lavarde, S., Chiappino, L., Alves, P., Astolfi, M., (2019) Les Minéraux du massif volcanique du Fogo, Ile de São Miguel, Açores, Portugal. Le Règne Mineral, 145, 30-50
Terceira Angra do Heroísmo ⓘ Algar do Carvão	[Opal] Forti, P. (2005). Genetic processes of cave minerals in volcanic environments: an overview. Journal of cave and Karst Studies, 67(1), 3-13.; Daza, D., Bustillo, M. A., Recio, C., Carvalho, M. R., & Nunes, J. C. (2014). Composición isotópica (δ¹⁸ O y δD) de espeleotemas silíceos en las cuevas volcánicas de Algar do Carvão y Branca Opala (Isla Terceira, Azores, Portugal). Estudios Geológicos, 70(2), 010.
Praia da Vitória ⓘ Branca Opala lava tube	[Opal] Daza, R., & Bustillo, M. A. (2014) Subaquatic opaline stromatolites in Branca Opala lava tube (Terceira, Azores Islands). 16th International Symposium of Volcanospeleology – 2nd Ecuadorean International Speleological Symposium, At Islas Galápagos (Ecuador), Volume: Abstracts Book
Beja Mértola Alcaria Ruiva ⓘ Balança Mine	[Opal] Pedro Alves collection and analytical data.
Odemira São Luís ⓘ Herdade dos Pendões Mine	[Opal-A var: Opal-AN] Alves, P. and Kampf, A.R. (2017) A mina de ferro e manganês da Herdade dos Pendões, Odemira, sudoeste de Portugal. Acopios, 8: 17-62. (in Portuguese).
Serpa Vila Nova de São Bento e Vale de Vargo ⓘ Cêrro da Oca Mine	[Opal-A var: Opal-AN] pedro alves collection
ⓘ Bragança	[Opal] Rui Nunes
Macedo de Cavaleiros ⓘ Morais	[Opal] Rui Nunes collection
ⓘ Mogadouro	[Opal] Rui Nunes collection
Castelo Branco Vila Velha de Ródão Vila Velha de Ródão ⓘ Sitio do Cobre Mine	[Opal-A var: Opal-AN] Martins da Pedra collection
Évora Estremoz Glória ⓘ Mostardeira Mine	[Opal-A var: Opal-AN] Rui Nunes collection 2012
Faro Alcoutim Martim Longo ⓘ Daroeira Mine	[Opal-A var: Opal-AN] Pedro Alves collection and analytical data.
Guarda Aguiar da Beira U.F Sequeiros e Grandiz ⓘ Penedo da Cabeça quarry	[Opal-A var: Opal-AN] Tiago Guia's mineral collection (self-collected)
ⓘ Ratoeira quarry	[Opal-A var: Opal-AN] Pedro Alves collection
Almeida Malpartida e Vale de Coelha ⓘ Portugal Nos. 1 & 2 quarries	[Opal-A var: Opal-AN] Felix Garcia Garcia Mineral Collection
Sabugal ⓘ Pousafoles do Bispo (Penalobo e Lomba)	[Opal-A var: Opal-AN] Guilherme Pedrosa collection, specimen from dealer
Leiria Alvaiázere Pelmá ⓘ Casal do Rei Mine	[Opal] LNEG - Laboratório Nacional de Energia e Geologia, Siorminp ID 1890 Diatomito
Bombarral Roliça ⓘ São Mamede Mine	[Opal] Direcção Geral de Minas
ⓘ Óbidos	[Opal] Rui Nunes
Santa Maria e São Pedro e Sobral da Lagoa ⓘ Quinta do Jardim Mine	[Opal] Rui Nunes 2012
ⓘ Lisbon	[Amber] Rui Nunes collection
ⓘ Cascais	[Amber] Rui Nunes
Cascais e Estoril ⓘ São João do Estoril	[Amber] rui nunes collection
ⓘ São Pedro do Estoril Beach	[Amber] Rui Nunes info 2018
Madeira Madeira Island Funchal São Martinho ⓘ Pico da Cruz	[Opal] Pedro Alves collection and analytical data.
Portalegre ⓘ Castelo de Vide	[Opal] Rui Nunes 2011
ⓘ Monforte	[Opal-A var: Opal-AN] Rui Nunes 2011
Nisa Santana ⓘ Faiopa Mine - São Miguel Mountain - Arneiro	[Opal] Martins da Pedra collection
Santarém ⓘ Rio Maior	[Opal] Rui Nunes 2011
Rio Maior ⓘ Espadanal Mines	[Opal] Rui Nunes 2011
Setúbal Barreiro Palhais e Coina Palhais ⓘ Palhais No. 1 Mine	[Opal] LNEG - Siorminp
Grândola Melides ⓘ Carvalhal Mine	[Opal] LNEG - Siorminp database information
Viana do Castelo Valença do Minho Gondomil e Safins ⓘ Eiras quarry	[Opal-A var: Opal-AN] Pedro Alves collection; Nuno Afonso collection (XRD-analysed)
Vila Real Vila Pouca de Aguiar Alfarela de Jales ⓘ Jales Mines (Jales Mining Field)	[Opal] Martins, S. A. B. (2018). Mineralizações auríferas de Jales, Gralheira e Raiz do Monte: estudo mineralógico e paragenético. o Mestrado em Geologia da Faculdade de Ciências da Universidade do Porto
Viseu Mangualde Quintela de Azurara ⓘ Nossa Senhora da Esperança quarry	[Opal-A var: Opal-AN]
Tavares (Chãs; Várzea e Travanca) ⓘ Bom Sucesso No. 4 quarry	[Opal-A var: Opal-AN] Rui Nunes collection
Sátão Decermilo e Vila Longa U.F Romãs ⓘ Carvalhal quarry	[Opal-A var: Opal-AN] Nuno Afonso collection
ⓘ Gralheira Mine	[Opal-A var: Opal-AN] Pedro Alves collection
Ferreira de Aves Aldeia Nova ⓘ Assunção Mine	[Opal-A var: Opal-AN] Van King
U.F Romãs Decermilo e Vila Longa ⓘ Romãs quarry	[Opal-A var: Opal-AN] Pedro Alves collection

Romania	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.

Alba County Roșia Montană ⓘ ~~Roşia Montană~~	[Opal] Woodside Collection
Buzău County ⓘ Colţi	[Amber] Neacşu, A. (2006) Remarks on The Geological Origin of Rumanite. Acta Mineralogica-Petrographica, Abstract Series 5, Szeged. p 83
Covasna County ⓘ Magyarhermány (Herculian)	[Opal] Zoltán Csata
Hunedoara County Băița Trestia ⓘ Trestia Mine	[Opal] Royal Ontario Museum specimen
Balșa ⓘ Techereu	[Opal] Primics, G. (1886): Das Vorkommen der derben Quarzvarietäten bei Tekerő. Földtani Közlöny, 16, 347-353.
ⓘ Gurasada	[Opal] Carpathian Journal of Earth and Environmental Sciences, October 2010, Vol. 5, No. 2, p. 89 - 99
Maramureș County Cavnic Suior Mine ⓘ Cremenea vein	[Opal] Damian, G., Ciobanu, C. L., Cook, N. J., & Damian, F. (2008). Bismuth sulphosalts from the galena-matildite series in the Cremenea vein, Suior, Baia Mare district, Romania. Neues Jahrbuch für Mineralogie-Abhandlungen, 185(2), 199-213.
Cernești ⓘ Trestia	[Opal] Dana, E., 1892, System of Mineralogy.
Șișești Dănești village ⓘ Dănești	[Opal] Marinel Kovacs, Alexandrina Fülöp, 2003, Neogene volcanism in Gutâi Mts., (Eastern Carpathians). A Review. Studia Universitatis, Babeș-Bolyai, Geologia, vol.48, 2003, p.3-16
Șurdești village ⓘ Șurdești	[Opal] Jude Radu (2010). An overview of the Oaș and Gutâi Neogene Metallogenetic District. Romanian Journal of Mineral Deposits, Mineral Resources of Carpathians area. 10th-12th September 2010, Baia Mare, Romania. vol 84, p.94-95
Târgu Lăpuș ⓘ Răzoare	[Opal] Udubasa, G., Hartopanu, P., Ilinca, G. (1996). The Regionally metamorphosed Fe-Mn Ore Deposit at Razoare, Preluca Mts., Romania. Romanian Journal of Mineralogy, 77, 3-20. Hirtopanu, Paulina and Udabasa, Gheorghe (2015): Minerals from Răzoare Mn-Fe deposit, Preluca Mountains, East Carpathians, Romania: New data. Romanian Journal of Mineral Deposits, 88, 11-28.
Neamț County Piatra Neamț ⓘ Almas Valley	[Amber] Heys Mineral Index 3rd ed.
Vâlcea County ⓘ Olanesti	[Amber] Heys Mineral Index 3rd ed.

Russia
Chelyabinsk Oblast Agapovsky District ⓘ Sakharinskoye Ni deposit (Sakharinsky Mine)	[Opal] https://webmineral.ru/deposits/item.php?id=4606
ⓘ Chelyabinsk coal basin	[Opal] Cesnokov, B., Kotrly, M. and Nisanbajev, T. (1998): Brennende Abraumhalden und Aufschlüsse im Tscheljabinsker Kohlenbecken - eine reiche Mineralienküche. Mineralien-Welt, 9 (3), 54-63 (in German).
Kartalinsky District ⓘ Verblyuzhegorskoye Cr deposit	[Opal] https://webmineral.ru/deposits/unit.php?id=3623515
Magnitogorsk Sakhara District (Sakharinskii) Sakhara massif ⓘ Sakhara Nickel mine	[Opal] Mikhailov, B.M. (2000): Lithology and Mineral Resources 35(4), 351-364.
Plastovsky District Svetlyi ⓘ Baturovsk quarry	[Opal] Pavel M. Kartashov analytical data
Vishnevye Mountains ⓘ Karavai Mt	[Opal] http://webmineral.ru/deposits/item.php?id=841
Irkutsk Oblast Lake Baikal area ⓘ Ol’khon Region	[Opal] Skovitina, T. M., E.V.Sklayrov, O.A.Sklyarova, A. B.Kotov, E.V.Tolmacheva, S.D.Velikoslavinsky (2014) Late Quaternary geyserites of the Ol’khon region (northern part of the Central Asian Orogenic Belt): geological setting, age and composition. in Abstract Volume IAGR Conference Series No. 20, pp.128–129
ⓘ Lena-Angara salt Basin	[Opal] Garrett, Donald E. (1998) Borates. Handbook of Deposits, Processing, Properties, and Use.
Zheleznogorsk ⓘ Korshunovskoye iron deposit	[Opal] http://webmineral.ru/deposits/item.php?id=1070
Kaliningrad Oblast Yantarny (Jantarny; Palmnicken) ⓘ Primorskoe amber deposit (Pal'mnickenskoe)	[Amber] Pavel M. Kartashov data; Krul, H. (1969) Geologische zwerftochten. N.V. W.J. Thieme & Cie - Zutphen, Netherlands, 161 pp. (in Dutch).
ⓘ Anna Amber mine	[Amber] Princeton Museum Record ID 2359
Kamchatka Krai Bystrinsky District ⓘ Apapel’sky springs	[Opal] Okrugin, V. M., Andreeva, E. D., Chubarov, V. M., Yablokova, D. A., Shishkanova, K. O., Chernev, I. I., & Chubarov, M. V. Sulfides of the Modern Kamchatka Hydrothermal Systems. Proceedings World Geothermal Congress 2015
Milkovsky District Tolbachik Volcanic field Great Fissure eruption (Main Fracture) Northern Breakthrough (North Breach) First scoria cone ⓘ Northern fumarole field	[Opal] Pekov, I. V., Zubkova, N. V., Britvin, S. N., Yapaskurt, V. O., Chukanov, N. V., Lykova, I. S., ... & Pushcharovsky, D. Y. (2015). New zinc and potassium chlorides from fumaroles of the Tolbachik volcano, Kamchatka, Russia: mineral data and crystal chemistry. III. Cryobostryxite, KZnCl3· 2H2O. European Journal of Mineralogy, 27(6), 805-812
Ust-Bolsheretsky District ⓘ Pauzhetskaya hydrothermal field	[Opal] Frolova, J. V., Ladygin, V. M., & Rychagov, S. N. (2010, April). Petrophysical alteration of volcanic rocks in hydrothermal systems of the Kuril-Kamchatka Island Arc. In Proceedings World Geothermal Congress (pp. 1-7). Rychagov, S. N., Sergeeva, A. V., & Chernov, M. S. (2017, November). Specific mineral associations of hydrothermal shale (South Kamchatka). In Doklady Earth Sciences (Vol. 477, pp. 1301-1306). Pleiades Publishing.
Ust-Kamchatsky District ⓘ Olkhovaya–1 River placer	[Opal] Sandimirova, E. I., Sidorov, E. G., Chubarov, V. M., Ibragimova, E. K., & Antonov, A. V. (2014). Native metals and intermetallic compounds in heavy concentrate halos of the Ol’khovaya-1 River, Kamchatsky Mys Peninsula, eastern Kamchatka. Geology of Ore Deposits, 56(8), 657-664.
Yelizovsky District Kronotsky Reserve ⓘ Uzon Caldera	[Opal] Karpov, G. A. (1991). Complex mercury-antimony-arsenic mineralization of the Uzon-Waiotapu type in modern hydrothermal systems. International Geology Review, 33(6), 599-611.; Kyle, J. E., Schroeder, P. A., & Wiegel, J. (2007). Microbial silicification in sinters from two terrestrial hot springs in the Uzon Caldera, Kamchatka, Russia. Geomicrobiology Journal, 24(7-8), 627-641.
ⓘ Fumarol'noye Lake	[Opal] Kirichenko, Ivan S., Lazareva, Elena V., Zhmodik, S.M., Dobrezov, N.L., Belyanin, D.K., Miroshnichenko, L.V. (2019) Modern Mineral Formation in the Thermal Lake Fumarolnoe (Uzon Caldera, Kamchatka) as a Key to Paleoreconstruction. Geology of Ore Deposits: 61: 747-755.
ⓘ Valley of Geysers	[Opal] Sergeeva, A., & Kiryukhin, A. (2019). Secondary minerals in the geyserites of the Geysers Valley (Kamchatka). In E3S Web of Conferences (Vol. 98, p. 08019). EDP Sciences.
ⓘ Bolshoy geyser	[Opal] Sergeeva, A., & Kiryukhin, A. (2019). Secondary minerals in the geyserites of the Geysers Valley (Kamchatka). In E3S Web of Conferences (Vol. 98, p. 08019). EDP Sciences.
ⓘ Mutnovskoe	[Opal] [Der Aufschluss 1995:4 p163-180]; Okrugin, V. M. (2004). Miocene to Quaternary center volcanic, hydrothermal and ore-forming activity in the Southern Kamchatka. In Metallogeny of the Pacific Northwest (Russian Far East)-Tectonics, Magmatism and Metallogeny of Active Continental Margin, Interim IAGOD Conference, Excursion Guidebook, Dalnauka, Vladivostok, 2004 (pp. 147-176).
ⓘ Mutnovsky volcano	[Opal] Bortnikova, S. B., Bortnikova, S. P., Manstein Yu, A., Kiryuhin, A. V., Vernikovskaya, I. V., & Palchik, N. A. (2009, February). Thermal springs hydrogeochemistry and structure at North-Mutnovskoe fumarole field (South Kamchatka, Russia). In Proceedings, thirty–fourth workshop on geothermal reservoir engineering. Stanford University, Stanford, CA, pp SGP-TR-187.; http://www.kscnet.ru/ivs/conferences/kasp/JKASP04_circular2.pdf
ⓘ Severo‐Mutnovsky thermal fields	[Opal] Frolova, J. V., Ladygin, V. M., & Rychagov, S. N. (2010, April). Petrophysical alteration of volcanic rocks in hydrothermal systems of the Kuril-Kamchatka Island Arc. In Proceedings World Geothermal Congress (pp. 1-7).
ⓘ Rodnikovoe	[Opal] [Der Aufschluss 1995:4 p.163-180]; Okrugin, V. M. (2004). Miocene to Quaternary center volcanic, hydrothermal and ore-forming activity in the Southern Kamchatka. In Metallogeny of the Pacific Northwest (Russian Far East)-Tectonics, Magmatism and Metallogeny of Active Continental Margin, Interim IAGOD Conference, Excursion Guidebook, Dalnauka, Vladivostok, 2004 (pp. 147-176).
Kursk Oblast Kursk Magnet Anomaly ⓘ Mikhailovskoe Fe deposit	[Opal] Tsekhovskii, Y.G., Lavrushin, V.Y., Kuleshov, V.N., Shchepetova, E.V., Stukalova, I.E., Nosik, L.P., Prokof’ev, V.Y., and Areshin, A.V. (2002): Lithology and Mineral Resources 37(3), 210-227.
Magadan Oblast Omsukchansky District ⓘ Ducat ore field	[Opal] Filimonova, L.G., and Trubkin, N.V. (2008): Geology of Ore Deposits 50(2), 135-144.
ⓘ Ducat Mine (Dukat Mine)	[Opal] Filimonova, L. G., Sivtsov, A. V., & Trubkin, N. V. (2010) Manganese oxides and associated minerals as constituents of dispersed mineralization of metasomatic rocks in the Dukat ore field. Geology of Ore Deposits, 52(4), 322-333.
ⓘ Moscow	[Opal-A var: Opal-AN] Pekin, A.A. [Пекин, А.А.] (2010) Minerals of Moscow [Минералы Москвы]. Rossiiskii Khimicheskii Zhurnal [Российский Химический Журнал], 54, 2, 115-123 (in Russian); Pekin, A.A. (2011) Minerals of Moscow. Russian Journal of General Chemistry, 81, 6, 1381-1391.
ⓘ Chertanovka upper reaches	[Opal] Pekin, A.A. [Пекин, А.А.] (2010) Minerals of Moscow [Минералы Москвы]. Rossiiskii Khimicheskii Zhurnal [Российский Химический Журнал], 54, 2, 115-123 (in Russian); Pekin, A.A. (2011) Minerals of Moscow. Russian Journal of General Chemistry, 81, 6, 1381-1391.
ⓘ Kamushki	[Opal] Pekin, A.A. [Пекин, А.А.] (2010) Minerals of Moscow [Минералы Москвы]. Rossiiskii Khimicheskii Zhurnal [Российский Химический Журнал], 54, 2, 115-123 (in Russian); Pekin, A.A. (2011) Minerals of Moscow. Russian Journal of General Chemistry, 81, 6, 1381-1391.
ⓘ Tyoply Stan	[Opal] Pekin, A.A. [Пекин, А.А.] (2010) Minerals of Moscow [Минералы Москвы]. Rossiiskii Khimicheskii Zhurnal [Российский Химический Журнал], 54, 2, 115-123 (in Russian); Pekin, A.A. (2011) Minerals of Moscow. Russian Journal of General Chemistry, 81, 6, 1381-1391.
Murmansk Oblast Khibiny Massif ⓘ Kukisvumchorr Mt	[Opal] Pekov, I.V. & Podlesnyi, A.S. (2004): Kukisvumchorr Deposit: Mineralogy of Alkaline Pegmatites and Hydrotermalites. Mineralogical Almanac, vol. 7, 140 pages + xxiv photo's pages
Lovozersky District Alluaiv Mountain ⓘ Umbozero North quarry	[Opal] Pavel M. Kartashov data
Engporr Mountain ⓘ Seidozeritovyi pegmatite #2	[Opal] Pavel M. Kartashov analytical data (2013)
Karnasurt Mountain Karnasurt mine ⓘ Palitra pegmatite	[Opal] Pekov, I.V. (2005) The Palitra pegmatite, Lovozero massif, Kola Peninsula, Russia. The Mineralogical Record: 36: 397-416.
Seidozero Lake ⓘ Lepkhe-Nel'm Mt	[Opal] Yakovenchuk, V.N., Pakhomovsky, Ya.A., Men’shikov, Yu.P., Mikhailova, J.A., and Ivanyuk, G.Yu. (2007): Canadian Mineralogist 45, 451-456.
ⓘ Selsurt Mountain	[Opal] My own collection
Orenburg Oblast Adamovsky District ⓘ Rechnoye cacholong deposit	[Opal] http://webmineral.ru/deposits/item.php?id=3037
Orsk Khalilovskii District Khabarninskii massif ⓘ Akkermanovskoe deposit	[Opal] Sharkov, A.A. (2009): Lithology and Mineral Resources 44(1), 19-35.
Khalilovskii massif (Khalilova) ⓘ Khalilovskoe Ni deposit	[Opal] Mikhailov, B.M. (2000): Lithology and Mineral Resources 35(4), 351-364.
ⓘ Sukhoy Izyak Paleoplacer	[Opal] Rakhimov, Ildar R., Dmitri E. Saveliev, Mikhail A. Rassomakhin, and Aidar A. Samigullin. (2022) "Chromian Spinels from Kazanian-Stage Placers in the Southern Pre-Urals, Bashkiria, Russia: Morphological and Chemical Features and Evidence for Provenance" Minerals 12, no. 7: 849. https://doi.org/10.3390/min12070849
Svetlyi District Buruktal District ⓘ Buruktal massif	[Opal] Mikhailov, B.M. (2000): Lithology and Mineral Resources 35(4), 351-364.
ⓘ Buruktal Mine	[Opal] Mikhailov, B.M. (2000): Lithology and Mineral Resources 35(4), 351-364.
Primorsky Krai Dalnegorsk Urban District ⓘ Dalnegorsk	[Opal] [MinRec 32:8]
ⓘ Nikolaevskiy Mine	[Opal] Dobovol'skaya, M. G., Baskina, V. A., Balashova, S. P., Kenisarin, A. M., Arakelyants, M. M., Klimachev, L. A., & Muravitskaya, G. N. (1990). Order of Formation of the Ores and Mafic Dikes of the Nikolayevsk Deposit (Southern Primor'ye). International Geology Review, 32(4), 391-403.
ⓘ Raduzhnoe Deposit	[Opal] Vysotskiy, S. V., Galkin, N. G., Barkar, A. V., Chusovitin, E. A., & Karabtsov, A. A. (2010). Hydrothermal precious opals of the Raduzhnoe deposit, north Primorye: The nature of the opalescence. Russian Journal of Pacific Geology, 4(4), 347-354.
ⓘ Sinancha Sn deposit	[Opal] Dobrovol’skaya, M.G., Genkin, A.D., Bortnikov, N.S., and Golovanova, T.I. (2008): Geology of Ore Deposits 50(1), 75-85.
ⓘ Sakha	[Opal] [World of Stones 12:49]
Aldansky District Upper Amga gold-mining district ⓘ Khokhoy Gold Ore Field	[Opal] Anisimova, G.S.; Kondratieva, L.A.; Kardashevskaia, V.N. (2020) Characteristics of Supergene Gold of Karst Cavities of the Khokhoy Gold Ore Field (Aldan Shield, East Russia). Minerals 10, 139.
Verkhneamginskaya auriferous zone ⓘ Upstream region of Khokhoy creek	[Opal] Kasatkin, Anatoly V., Galina S. Anisimova, Fabrizio Nestola, Jakub Plášil, Jiří Sejkora, Radek Škoda, Evgeniy P. Sokolov, Larisa A. Kondratieva, and Veronika N. Kardashevskaia. (2022) "Amgaite, Tl3+2Te6+O6, a New Mineral from the Khokhoyskoe Gold Deposit, Eastern Siberia, Russia" Minerals 12, no. 9: 1064. https://doi.org/10.3390/min12091064
Polar Yakutia Alazeya river basin ⓘ Mustakh stream	[Opal] Igor Savin data
Sakhalin Oblast Kuril Islands (Kurile Islands) Kurilsky District Iturup Island ⓘ Baranskogo hydrothermal field	[Opal] Frolova, J. V., Ladygin, V. M., & Rychagov, S. N. (2010, April). Petrophysical alteration of volcanic rocks in hydrothermal systems of the Kuril-Kamchatka Island Arc. In Proceedings World Geothermal Congress (pp. 1-7).
Bogatyr' Range ⓘ Novoe sulphur deposit	[Opal] Znamenskii V.S., Lebedev L.M., Sidorenko G.A. (1970) On molybdenite from middle-cretaceous volcanic rocks of Iturup island (Kuril Islands), - DAN USSR, v.193, N4, pp. 898-901 (in Rus.).
Severo-Kurilsky District Atlasov Island Alaid volcano ⓘ Olimpiyskiy Fissure	[Opal] Vergasova, L.P. [Вергасова, Л.П. ] (1977) Olimpiyiskiy breakthrough fumarole minerals [Фумарольные минералы прорыва Олимпийского]. Bulletin of the Kamchatka Volcanologic Station [Бюллетень вулканологической станции на Камчатке], 53, 77–89 (in Russian); Zhitova, E.S., Anikin, L.P., Sergeeva, A.V., Ismagilova, R.M., Rashidov, V.A. , Chubarov, V.M., and Kupchinenko, A.N. [Житова, Е.С., Аникин, Л.П., Сергеева, А.В., Исмагилова, Р.М., Рашидов, В.А., Чубаров, В.М., и Купчиненко, А.Н.] (2020) Volborthite Occurrence at the Alaid Volcano (Atlasov Island, Kuril Islands, Russia) [Проявление фольбортита на вулкане Алаид (о. Атласова, Курильские острова, Россия)] Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva [Записки Всероссийского Mинералогического Oбщества], 149, 3, 78–95 (in Russian).
Paramushir Island ⓘ Ebeco Volcano (Ebeko Volcano)	[Opal] Shevko, E. P., Bortnikova, S. B., Abrosimova, N. A., Kamenetsky, V. S., Bortnikova, S. P., Panin, G. L., & Zelenski, M. (2018). Trace Elements and Minerals in Fumarolic Sulfur: The Case of Ebeko Volcano, Kuriles. Geofluids, 2018.
Yuzhno-Kurilsky District Kunashir Island ⓘ Mendeleev volcano (Ruasu-dake)	[Opal] L.M. Lebedev data
Sakhalin Island Dolinsky district Starodubskoye ⓘ Starodubskoe amber deposit	[Amber] Pavel M. Kartashov data
ⓘ Yantarnaya river	[Amber] Pavel M. Kartashov data
Nevelsky District ⓘ Unnamed mudstone	[Opal] Koichi Momma, Toshiro Nagase, Robert Jenkins, Yusuke Miyajima, Kenichiro Tani, Akira Ijiri, Sergei Kasatkin, Igor Chekryzhov, Ritsuro Miyawaki (2018) Occurrences and crystal structures of melanophlogite from Sakhalin, Far East Russia. in abstracts of the 22nd IMA Meeting Melbourne p 238
ⓘ Zamiraylova Golova cape	[Opal] Koichi Momma, Toshiro Nagase, Robert Jenkins, Yusuke Miyajima, Kenichiro Tani, Akira Ijiri, Sergei Kasatkin, Igor Chekryzhov, Ritsuro Miyawaki (2018) Occurrences and crystal structures of melanophlogite from Sakhalin, Far East Russia. in abstracts of the 22nd IMA Meeting Melbourne p 238
Samara Oblast ⓘ Vodinskoe deposit	[Opal] Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
Stavropol Krai Pyatigorsk Lermontovskoe U Deposit Beshtau Mountain ⓘ Mine no. 1	[Opal]
ⓘ Gremuchka ore zone	[Opal] Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
Sverdlovsk Oblast Beryozovsky ⓘ Berezovsk deposit	[Opal]
Ural Mountains ⓘ Polar Urals	[Opal] [Mineralien Welt 6/92:62]
Yamalo-Nenets Autonomous Okrug Labytnangi ⓘ Ozernoe Occurrence	[Opal] Murzin, Valery, Galina Palyanova, Татiana Mayorova, and Tatiana Beliaeva. (2022) "The Gold–Palladium Ozernoe Occurrence (Polar Urals, Russia): Mineralogy, Conditions of Formation, Sources of Ore Matter and Fluid" Minerals 12, no. 6: 765. https://doi.org/10.3390/min12060765

Rwanda
Western Province Ngororero District Muhororo ⓘ Buranga pegmatite	[Opal] Daltry, V.D.C. and von Knorring, O. (1998) Type-mineralogy of Rwanda with particular reference to the Buranga pegmatite. Geologica Belgica: 1: 9-15.

Saint Lucia
Soufriere ⓘ Sulphur Springs	[Opal] McKeeby, B. (2017). Weathering and Sulfate Formation in Sulfur Springs St. Lucia; A Mars Analogue Site. Masters Thesis, Wesleyan University, Middletown, Connecticut

Saudi Arabia
Mecca Region ⓘ Hibashi Cave	[Opal] Saudi Geological Survey Open-File Report SGS-OF-2004-12, 68 p.

Serbia
Central Serbia Jablanica District Medveđa Lece volcanic complex ⓘ Bučumet deposit	[Opal] Miladinovic, Z., Simic, V., Jelenkovic, R., & Ilic, M. (2016). Gemstone deposits of Serbia. Geologica Carpathica, 67(3), 211.
Moravica District Gornji Milanovac ⓘ Boblija deposit	[Opal] Miladinovic, Z., Simic, V., Jelenkovic, R., & Ilic, M. (2016). Gemstone deposits of Serbia. Geologica Carpathica, 67(3), 211.
Pčinja District Bujanovac ⓘ Bujanovac occurrence	[Opal] http://giseurope.brgm.fr/GIS_SERBIA/SerbiaOreDeposits.pdf
Raška District Kraljevo City ⓘ Lojanik deposit	[Opal] Miladinovic, Z., Simic, V., Jelenkovic, R., & Ilic, M. (2016). Gemstone deposits of Serbia. Geologica Carpathica, 67(3), 211.
Šumadija District Knic ⓘ Vučkovica deposit	[Opal] Kurešević, L., Vušović, O., and Delić-Nikolić, I. (2022) Vučkovica Carbonate-silica gemstone deposit (Central Serbia): Geologic properties, genetic processes and deposition age. Geologica Macedonica, 36: 2: 105–118; https://doi.org/10.46763/GEOL22362105k
Kragujevac ⓘ Ramaća deposit	[Opal] Miladinovic, Z., Simic, V., Jelenkovic, R., & Ilic, M. (2016). Gemstone deposits of Serbia. Geologica Carpathica, 67(3), 211.

Slovakia
Banská Bystrica Region Banská Bystrica District Badín ⓘ Badín Andesite quarry	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Horné Pršany ⓘ Horné Pršany outcrops	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Hrochoť ⓘ Kyslinky	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Ľubietová ⓘ Jamešná deposit	[Opal-A var: Opal-AN] Mesiarkinová, M. & Ozdín, D. (2009) Study of hydrothermal SiO2 mineralization on the locality Ľubietová - Jamešná (Slovakia). Mitt. Österreich. Mineralog. Gesellschaft, 155, p. 101.
ⓘ Posádka	[Opal] Slavkay M., et al. (2004): Ložiská nerastných surovín Slovenského rudohoria. Zv. 2, ŠGÚDŠ Bratislava, p. 198.
ⓘ Tri Vody	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Francisci mine	[Opal] Slavkay M., et al. (2004): Ložiská nerastných surovín Slovenského rudohoria. Zv. 2, ŠGÚDŠ Bratislava, p. 198.
Malachov ⓘ Malachov mercury deposit	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Poniky ⓘ Ponická Huta	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Povrazník ⓘ Povrazník occurrence	[Opal] Ďuďa R., 1996: Slovenské opály. Minerál,Brno, IV, 4, 254 - 258
ⓘ Strelníky	[Opal-A var: Opal-AN] Pauliš,P.,Ďuďa,R.,2002: Nejzajímavejší mineralogická naletište Slovenska. Kuttna,K.Hora, 136p
Tajov ⓘ Tajov arsenic deposit	[Opal] Koděra, M. a kol.: Topografická mineralogie Slovenska. Sv. 3 Sed-Ž, Bratislava, Veda 1990, s. 1273-5.
Banská Štiavnica District Banská Belá Banská Belá Au-Ag deposit ⓘ Zeolite occurrence	[Opal] Koděra M., Andrusovová-Vlčeková G., Belešová O., Briatková D., Dávidová Š., Fejdiová V., Hurai V., Chovan M., Nelišerová E., Ženiš P., 1986-1990: Topografická mineralógia Slovenska. I-III. Veda, Bratislava, 1592 p. (in Slovak)
ⓘ Banská Štiavnica	[Opal-A var: Opal-AN] Lexa, J., Štohl, J., & Konečný, V. (1999). The BanskáŠtiavnica ore district: relationship between metallogenetic processes and the geological evolution of a stratovolcano. Mineralium Deposita, 34(5-6), 639-654.
ⓘ Banky	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Červená Studňa	[Opal] Lexa, J., Štohl, J., and Konečný, V. (1999): Mineralium Deposita 34, 639-654.
ⓘ Kremenisko	[Opal] S.ŠIMKO
ⓘ Banský Studenec	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Dekýš	[Opal] Lexa, J., Štohl, J., and Konečný, V. (1999): Mineralium Deposita 34, 639-654.
ⓘ Podhorie	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Svätý Anton	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Brezno District ⓘ Jarabá	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Detva District ⓘ Detva	[Opal-A var: Opal-AN] Koděra, M., Andrusovová-Vlčeková, G., Belešová, O., Briatková, D., Dávidová, Š., Fejdiová, V., Hurai, V., Chovan, M., Nelišerová, E., Ženiš, P. (1986-1990): Topografická mineralógia Slovenska. I-III. Veda, Bratislava, 1592 p.
ⓘ Hriňová	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Zánemecká	[Opal] Ivanov M. (1979): Genéza mangánových rudných výskytov medzi Detvou a Hriňovou. Geol. Práce, Správy, 73,173-186.
ⓘ Vígľašská Huta-Kalinka	[Opal] Rojkovičová,Ľ., 1982: Rudná mineralizácia v Javorí. Min.Slovaca, 14,5,461 – 470
Krupina District ⓘ Bzovík	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Hontianske Nemce ⓘ Sitnianska Lehôtka	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Lučenec District ⓘ Belina	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Bulhary	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Revúca District Sirk ⓘ Železník iron deposit	[Opal] Grecula,P. et al., 1995: Ložiska nerastných surovín Slovenského rudohoria. Zväz.1, Bratislava, 834 s
Veľký Krtíš District ⓘ Pôtor	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Žarnovica District Hodruša-Hámre ⓘ Hodruša-Hámre mines	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Nová Baňa Brehy ⓘ Brehy quarry	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Nová Baňa deposit	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Žarnovica ⓘ Žarnovická Huta	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Žiar nad Hronom District ⓘ Bartošova Lehôtka	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Hliník nad Hronom ⓘ Hliník nad Hronom rhyolite quarry	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Jastrabá	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Ihráčska Píla wood opal occurrence	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Kopernica	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Kremnica ⓘ Kremnica Au-Ag deposit	[Opal-A var: Opal-AN] Ďuďa, R. (1993) Die mineralien der Gold und Silber - lagersttäte von Kremnitz ( Kremnica) in der Slowakei. Mineralien Welt /Haltern,Nemecko/: 5: 20-32.
Ladomerská Vieska ⓘ Ladomerská Vieska quarry	[Opal] Daniel Ozdín collection
ⓘ Lutila	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Nevoľné	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Prochot	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Sklené Teplice	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Slaská ⓘ Slaská quarry	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Stará Kremnička ⓘ Stará Kremnička quarry	[Opal] Pauliš,P.,Ďuďa,R.,2002: Nejzajímavejší mineralogická naletište Slovenska. Kuttna,K.Hora, 136p
Zvolen District Lešť ⓘ Švihranka	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Bratislava Region Pezinok District Pezinok ⓘ Ferdinand and Augustín Mine	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Kolársky vrch deposit	[Opal] [MinRec 31:153-162]
Košice Region Gelnica District Gelnica ⓘ Gelnica - Cechy	[Opal] Pauliš P., Ďuďa R., 2002: Nejzajimavejší mineralogická nalezište Slovenska. Kuttna, Kutná Hora, 134p.
Košice-okolie District ⓘ Herľany	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Hodkovce	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Kalša	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Kecerovský Lipovec	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Košický Klečenov ⓘ Dargov quarry	[Opal-A var: Opal-AN] Pauliš P., Ďuďa R., 2002: Nejzajimavejší mineralogická nalezište Slovenska. Kuttna, Kutná Hora, 134p.
ⓘ Ruskov	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Slanec ⓘ Slanec quarry	[Opal-A var: Opal-AN] Pauliš P., Ďuďa R., 2002: Nejzajimavejší mineralogická nalezište Slovenska. Kuttna, Kutná Hora, 134p.
ⓘ Vyšná Kamenica	[Opal] Matúš Škutka
Michalovce District Jovsa ⓘ Opal occurrence	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Poruba pod Vihorlatom ⓘ Quartzite outcrops	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Trnava pri Laborci	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Vinné ⓘ Šutová	[Opal] Koděra M., Andrusovová-Vlčeková G., Belešová O., Briatková D., Dávidová Š., Fejdiová V., Hurai V., Chovan M., Nelišerová E., Ženiš P. (1986-1990): Topografická mineralógia Slovenska. I-III. Veda, Bratislava, 1-1592. (in Slovak)
Rožňava District ⓘ Betliar	[Opal-A var: Opal-AN] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
ⓘ Dobšiná	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
ⓘ Teliatko serpentinite body	[Opal] Ozdín D. & Števko M., 2010: Unikátny výskyt achátov v serpentinizovaných peridotitoch v Dobšinej. Minerál, 18, 4, 331-335.
Kečovo ⓘ Domica Cave	[Opal] Cílek, V. (1999) Mineralogické výskumy v jeskyni Domica. Aragonit, 4, 9–11.
Ochtiná ⓘ Hrádok hill	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Ochtinská aragonite cave	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Sobrance District ⓘ Remetské Hámre	[Opal-A var: Opal-AN] Bacsó,Z.,Ďuďa,R.,1988: Metalogenéza a rudné formácie rudného poľa Remetské Hámre. Min.Slovaca,Bratislava, 3, 193-220p
ⓘ Morské oko	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Vyšné Nemecké ⓘ Močidlá	[Opal] Matúš Škutka
Spišská Nová Ves District ⓘ Markušovce	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Trebišov District ⓘ Brezina	[Opal-A var: Opal-AN] Pauliš P., Ďuďa R., 2002: Nejzajimavejší mineralogická nalezište Slovenska. Kuttna, Kutná Hora, 134p.
Kuzmice ⓘ Quartz veins	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Slivník	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Zemplín ⓘ Chalcedony occurrence	[Opal] Kaličiak, M., Ďuďa, R., 1996: Geolgický vývoj, stavba a metalogenéza neovulkanitov na Východnom Slovensku. Manuskript, Archív Geofond, Bratislava, 83p
Nitra Region Levice District ⓘ Brhlovce	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Devičany	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Kalná nad Hronom ⓘ Mochovce	[Opal] Albert Russ specimens
ⓘ Kozárovce	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Levice	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Pukanec	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Veľký Ďur ⓘ Rohožnica	[Opal] Wood Opals From Velky Dur,Mineral no.3,2006,Illasova and Turnovec
Prešov Region Kežmarok District ⓘ Holumnica	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Poprad District Hôrka ⓘ Kišovce	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Poprad ⓘ Kvetnica	[Opal] Pauliš,P.,Ďuďa,R.,2002: Nejzajímavejší mineralogická naletište Slovenska. Kuttna,K.Hora, 136p
Tatranská Javorina ⓘ Podspády	[Amber] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Vikartovce	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Prešov District ⓘ Červenica	[Opal] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Dubník	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Libanka	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Jozef adit	[Opal-A var: Opal-AN] Personally collected by S.Šimko in 1994
ⓘ Slávik adit	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Lesíček	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Vyšná Šebastová ⓘ Maglovec quarry	[Opal] Ďuďa,R., et al., 1981: Mineralógia severnej časti Slanských vrchov. Min.Slovaca, Monografia 2, 98s
Zlatá Baňa ⓘ Zlatá Baňa deposit	[Opal-A var: Opal-AN] Duda et. all.,1981:Minerály severnej časti Slanských vrchov. Min.Slovca,Monografia 2,Bratislava, 98 p
ⓘ Antimony deposit	[Opal] Koděra M., Andrusovová-Vlčeková G., Belešová O., Briatková D., Dávidová Š., Fejdiová V., Hurai V., Chovan M., Nelišerová E., Ženiš P. (1986-1990): Topografická mineralógia Slovenska. I-III. Veda, Bratislava, 1592 p. (in Slovak)
ⓘ Base metal deposit	[Opal] Ďuďa R., Baláž B. (2001): Minerály na ložiskách zlatobanského stratovulkánu. Minerál, 9, 4, 248-269 (in Slovak).
Snina District ⓘ Ladomirov	[Opal-A var: Opal-AN] Pauliš,P.,Ďuďa,R.,2002: Nejzajímavejší mineralogická naletište Slovenska. Kuttna,K.Hora, 136p
Stará Ľubovňa District Šarišské Jastrabie ⓘ Šarišské Jastrabie deposit	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Vranov nad Topľou District Banské ⓘ Banské outcrop	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
ⓘ Hermanovce nad Topľou	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Juskova Voľa ⓘ Juskova Voľa quarry	[Opal] Duda et all.,:Mineralógia severnej časti Slanských vrchov. Min.Slovaca,Monografia 2,Bratislava, 98 p
Vechec ⓘ Vechec quarry	[Opal-A var: Opal-AN] Ďuďa,R., et al., 1981: Mineralógia severnej časti Slanských vrchov. Min.Slovaca, Monografia 2, 98s
ⓘ Zámutov	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Trenčín Region Prievidza District ⓘ Handlová	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
ⓘ Handlová coal mine	[Opal-A var: Opal-AN] Slavomír Šimko
ⓘ Vysoká hill	[Opal] S.Šimko
Lehota pod Vtáčnikom ⓘ Lehota pod Vtáčnikom quarries	[Opal] Gabriel Gajarsky specimen
Trnava Region Trnava District Lošonec ⓘ Lošonec Quarry	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Žilina Region Dolný Kubín District ⓘ Zázrivá	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p
Liptovský Mikuláš District Malužiná ⓘ Svidovo	[Opal] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590k
Partizánska Lupča ⓘ Magurka	[Opal-A var: Opal-AN] Koděra, M. et al., 1986 a 1990 : Topografická mineralógia Slovenska, diel 1- 3, Veda – Vydavateľstvo SAV, Bratislava, 1990, 1 – 1590
Turčianske Teplice District ⓘ Turček	[Opal] Koděra et all.,1990: Topografická mineralógia Slovenska, I-III, 1590p

Somaliland
ⓘ Awdal	[Opal] Wolfgang Hampel specimen
Jodha ⓘ Qabri Bahar	[Opal] Journal of Gemmology, 28:81-84 (2002).

South Africa
Gauteng City of Tshwane Metropolitan Municipality ⓘ Vergenoeg Mine	[Opal] Atanasova, M., Cairncross, B. and Windisch, W.R. (2016) Microminerals of the Bushveld Complex, South Africa. Popular Geoscience Series 6, Council for Geoscience, Pretoria, South Africa
West Rand District Municipality Mogale City Local Municipality Muldersdrift ⓘ Muldersdrif ultramafic complex	[Opal] Anhaeusser, C.R., (1978) The Geology And Geochemistry Of The Muldersdrif Ultramafic Complex, Krugersdorp District. Economic Geology Research Unit, University Of The Witwatersrand Johannesburg. Information Ciruclar No. 117
KwaZulu-Natal Ugu District Municipality ⓘ Marble Delta	[Opal] Cairncross, B., Dixon, R. (1995) Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, PO Box 44283, Linden 2104, South Africa.
Limpopo Vhembe District Municipality Soutpansberg Range ⓘ Vivo	[Opal] Cairncross, B., Dixon, R. (1995) Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, PO Box 44283, Linden 2104, South Africa.
Waterberg District Municipality Modimolle-Mookgophong Local Municipality Mookgophong ⓘ Buffalo Fluorspar Mine	[Opal-A var: Opal-AN] Wolfgang R. Windisch personal list.
Mpumalanga Ehlanzeni District Municipality Mbombela Local Municipality Barberton ⓘ Bon Accord Ni deposit	[Opal] De Waal, S.A., (1969). Nickel minerals from Barberton, South Africa: I Ferroan trevorite. American Mineralogist, 54, 1204-1208.
Mbombela ⓘ Mbobo Mkulu Cave	[Opal] Martini, J.E.J. et al (1997), "Mbobo Mkulu Cave, South Africa", in "Cave Minerals of the World" (1997)
Nkangala District Municipality Victor Khanye Local Municipality Delmas ⓘ Argent	[Opal] Atanasova, M., Cairncross, B. and Windisch, W.R. (2016) Microminerals of the Bushveld Complex, South Africa. Popular Geoscience Series 6, Council for Geoscience, Pretoria, South Africa, 435 pp
North West Bojanala Platinum District Municipality Madibeng Local Municipality Brits ⓘ Slipfontein	[Opal] Atanasova, M., Cairncross, B. and Windisch, W.R. (2016) Microminerals of the Bushveld Complex, South Africa. Popular Geoscience Series 6, Council for Geoscience, Pretoria, South Africa, pg 181
Moses Kotane Local Municipality Pilanesberg Alkaline Ring Complex ⓘ Pilanesberg Mountain	[Opal] Cairncross, B., Dixon, R. (1995) Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, PO Box 44283, Linden 2104, South Africa.
Northern Cape Kalahari manganese field Black Rock ⓘ Black Rock Mine	[Opal] Am Min 53:495
Hotazel ⓘ Hotazel Mine	[Opal] Von Bezing, K. L. et al. (1991) The Kalahari manganese field: An Update, Mineralogical Record 22(4) pp 289.
Namakwa District Municipality Khâi-Ma Local Municipality ⓘ Pella	[Opal] Cairncross, B. and Dixon, R., (1995) Cairncross, B., Dixon, R. (1995) Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, PO Box 44283, Linden 2104, South Africa.. The Geological Society of South Africa, p 228;
Nama Khoi Local Municipality Henkries ⓘ Henkries uranium deposit	[Opal] Eriksson, P.G. (1997): Mineralium Deposita 32, 419-422.
ⓘ Postmasburg manganese field	[Opal] Cairncross, B., Dixon, R. (1995) Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, PO Box 44283, Linden 2104, South Africa.
Western Cape West Coast District Municipality Cederberg Local Municipality ⓘ Elands Bay Cave	[Opal] Miller, C. E., Mentzer, S. M., Berthold, C., Leach, P., Ligouis, B., Tribolo, C., ... & Porraz, G. (2016). Site-formation processes at Elands Bay Cave, South Africa. Southern African Humanities, 29(1), 69-128.

South Korea
Gangwon Province Chongson-gun Tong-myon Hwaam-ni ⓘ Hwapyo Mine	[Opal] Kinosaki, Y. (1941) Journal of the Mineralogical Society of Korea, 24, 5.

Spain
Andalusia Almería Bayarque ⓘ San José Mine	[Opal] Propuestas para explotación de mineral de mercurio en la Península Ibérica. Datos complementarios para la investigación en el S.E.", ITGE (Madrid, 1968)
Cuevas del Almanzora ⓘ Los Lobos	[Opal] Calvo, M. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.
ⓘ Volcanica quarry	[Opal] Calvo, M. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.
Las Tres Villas Escullar ⓘ Minas del General (Cortijo Virginia)	[Opal] José Miguel Sola
Níjar Cabo de Gata volcanic complex ⓘ Agua Amarga	[Opal] - Calvo Rebollar, M. (2016). Minerales y Minas de España, vol. VIII. Cuarzo y otros minerales de la sílice. Fundación Gómez Pardo, E.T.S. Ing. de Minas, Madrid, 399 pgs.
ⓘ La Isleta del Moro	[Opal] - Calvo Rebollar, M. (2016) Minerales y Minas de España. Vol. VIII, Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo, 399 pages (in Spanish, with plate captions also in English).
ⓘ Rodalquilar	[Opal] Joaquim Mollfulleda, Minerales, Omega, 1996
Granada Galera ⓘ Gypsum outcrop	[Opal] Calvo, M. (2016). Minerales y Minas de España. Vol VIII.Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.
Huelva Zufre ⓘ Juanito Mine	[Opal] Calvo, M. (2016). Minerales y Minas de España. Vol VIII.Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.
Jaén Pozo Alcón ⓘ El Negral quarry	[Opal] José Miguel Sola. Multiple methods, XRD thin sheet, XRD, Optical, electrical and chemical properties. There are other silicates that we have not been able to identify due to the lack of adequate methods. In our studies we have not seen analcime.
Málaga Mijas ⓘ Por Fin mine	[Opal] Romero Silva JC (2003) Minerales y Rocas de la provincia de Malaga. 318 pp. Published by CEDMA Malaga County Council. Spain
Aragon Teruel Loscos ⓘ Road to Bádenas	[Opal] Calvo, M. (2008) Minerales de Aragón. Prames (Zaragoza) 463 pages
ⓘ Utrillas	[Amber] Penalver, E., Delclos, X., & Soriano, C. (2007). A new rich amber outcrop with palaeobiological inclusions in the Lower Cretaceous of Spain. Cretaceous Research, 28(5), 791-802.
ⓘ Coal outcrops	[Amber] Rui Nunes 2018
ⓘ San Just	[Amber] Penalver, E., Delclos, X., & Soriano, C. (2007). A new rich amber outcrop with palaeobiological inclusions in the Lower Cretaceous of Spain. Cretaceous Research, 28(5), 791-802.
Zaragoza Morés Purroy ⓘ San Pedro Mine (Toria Quarry)	[Opal] Calvo, M. (2008) Minerales de Aragón. Prames (Zaragoza) 463 pp
Canary Islands Las Palmas Province ⓘ Gran Canaria	[Opal] Extra Lapis - English No. 10 Opal
Agaete ⓘ Barranco de Guayedra	[Opal] María Jesús Mediavilla collection
La Aldea de San Nicolás Anden Verde ⓘ Montaña Aserrada	[Opal] Mullis, J., and Sigl, F. (1982) Die Entstehungsgeschichte von Opal, Chalcedon und Quarz von Gran Canaria. Schweizer Strahler, 6,155-176.
Las Palmas de Gran Canaria ⓘ Cantera de La Esfinge	[Opal-A var: Opal-AN] Alex Hansen Machín (2009). Volcanología y geomorfología de la etapa de rejuvenecimiento plio-pleistocena de Gran Canaria (Islas Canarias). Tesis doctoral. Personally collected in January 2013
ⓘ Mogán	[Opal-A var: Opal-AN] Graetsch, H. and I. Topalovic-Dierdorf: MAS NMR spectra of hyalite from Gran Canaria. Chemie der Erde. 56: (1996).387-391. 770
ⓘ Degollada de Veneguera	[Opal-A var: Opal-AN] Zeolite collcetion of Volker Betz
ⓘ Lomo de Veneguera	[Opal] - Ternes, B. (1995): Fundstellen im Südwesten Gran Canarias. Lapis 20 (1), 57-59 (in German).
Lanzarote Tinajo ⓘ Tinguatòn	[Opal] Francesco Sauro, Matteo Massironi, Riccardo Pozzobon, Jesùs Martinez Frìas, Paolo Gasparetto, Sergio Pegoraro, Fabio Tosato (2021) Studio mineralogico del cono di scorie di Tinguatòn (Lanzarote, Isole Canarie) tramite l'analisi dei campionamenti svolti nei programmi Pangaea e Pangaea-X dell'Agenzia Spaziale Europea, Micro vol. 19, 3-2021 pp. 174-192 Francesco Sauro, Matteo Massironi, Riccardo Pozzobon, Jesùs Martinez Frìas, Paolo Gasparetto, Sergio Pegoraro, Fabio Tosato (2021) Studio mineralogico del cono di scorie di Tinguatòn (Lanzarote, Isole Canarie) tramite l'analisi dei campionamenti svolti nei programmi Pangaea e Pangaea-X dell'Agenzia Spaziale Europea, Micro vol. 19, 3-2021 pp. 174-192 Francesco Sauro, Matteo Massironi, Riccardo Pozzobon, Jesùs Martinez Frìas, Paolo Gasparetto, Sergio Pegoraro, Fabio Tosato (2021) Studio mineralogico del cono di scorie di Tinguatòn (Lanzarote, Isole Canarie) tramite l'analisi dei campionamenti svolti nei programmi Pangaea e Pangaea-X dell'Agenzia Spaziale Europea, Micro vol. 19, 3-2021 pp. 174-192
Santa Cruz de Tenerife Province Tenerife Santa Cruz de Tenerife Taganana ⓘ Nepheline outcrop	[Opal] Bustillo, M.A. & Martínez-Frías, J. (2003): Green opals in hydrothermalized basalts (Tenerife Island, Spain): alteration and aging of silica pseudoglass. Journal of Non-Crystalline Solids 323, 27-33.
Cantabria ⓘ Comillas	[Amber] Rui Nunes' mineral collection (2018)
Herrerías ⓘ El Soplao outcrop	[Amber] Najarro, M., Penalver, E., PÉREZ‐DE LA FUENTE, R., ORTEGA‐BLANCO, J., MENOR‐SALVÁN, C., Barron, E., ... & Tornos, F. (2010). Review of the El Soplao amber outcrop, Early Cretaceous of Cantabria, Spain. Acta Geologica Sinica, 84(4), 959.
Miengo Cuchía ⓘ Cuchía quarry	[Amber] Rui Nunes 2018
Reocín ⓘ Reocín Mine	[Amber] Collect. José Rafael González López
Castile-La Mancha Albacete ⓘ Elche de la Sierra	[Opal] Juan Miguel Casanova Honrubia information
Hellín ⓘ Agramón	[Opal] INTAN (Barcelona) and Stefan Schorn specimens
ⓘ Embalse de Camarillas	[Opal] INTAN specimens (Barcelona)
Cancarix lamproite intrusion ⓘ Sierra de las Cabras ?	[Opal] Juan Miguel Segura specimen
ⓘ Coto Menor mines	[Opal] MTI Mineralogía Topográfica Ibérica, 2009
Ciudad Real Bolaños de Calatrava ⓘ Herrerías Volcano (Las Herrerías quarry)	[Opal] Calvo, M., Viñals, J., Sanz, A. and Martí, J. (2013). Zeolites and asociated minerals in the vacuoles of some of the Campo de calatrava volcanoes - Ciudad Real, Spain. Mineral Up,3, 54-69
ⓘ Campo de Calatrava volcanoes	[Opal-A var: Opal-AN] Martins da Pedra collection
Castile and Leon Segovia ⓘ Alconada de Maderuelo	[Opal] - Fernández Macarro, B., Armenteros, I., Blanco, J.A. (1988). Procesos de alteración y paleosuelos ligados a la sedimentación miocena del NE de Segovia, depresión del Duero. Acta Geológica Hispánica, v.23, 269-281.
ⓘ Miocene outcrops	[Opal] - Fernández Macarro, B., Armenteros, I., Blanco, J.A. (1988). Procesos de alteración y paleosuelos ligados a la sedimentación miocena del NE de Segovia, depresión del Duero. Acta Geológica Hispánica, v.23, 269-281.
Zamora ⓘ La Tuda	[Opal] Jordi Fabre
Catalonia Barcelona Baix Llobregat Gavà Bruguers ⓘ Elvira Mine (Rocabruna Mines)	[Opal] Rosell-Riba, J., Díaz-Acha, Y., Ibáñez-Insa, J., Campmany, J. (2022): Mines i minerals de la serra de les Ferreres. Les mines de Rocabruna, Bruguers, Gavà, el Baix Llobregat, Catalunya. Ed. Grup Mineralògic Català. Barcelona. 136 pàg.
Barcelonès Barcelona city ⓘ Montjuïc	[Opal] Carles Curto Mila collection
Maresme Tordera ⓘ Rialls quarry (Montpalau quarry)	[Opal-A var: Opal-AN] Marc C collection
Osona ⓘ Viladrau	[Opal] Alfredo Petrov field observations
Vallès Occidental-Baix Llobregat Sant Cugat del Vallès-El Papiol ⓘ Berta quarry and mine	[Opal]
Vallès Occidental Montcada i Reixac ⓘ Montcada Hill Quarry	[Opal] Mineralogistes de Catalunya (1997), VII (1): 34-55
Vallès Oriental Aiguafreda ⓘ Els Frares quarry (Riera d'Avencó; Riera d'Avençó)	[Opal] Bareche, E. (2005) "Els minerals de Catalunya. Segle XX" Grup Mineralògic Català, Barcelona, 269 pages
Sant Fost de Campsentelles ⓘ Can Donadeu quarry	[Opal] Laura Palacios Pérez, Minerals i roques, Pòrtic Natura, 2003
Girona Caldes de Malavella ⓘ Camp dels Ninots	[Opal] Laura Palacios Pérez, Minerals i roques, Pòrtic Natura, 2003
ⓘ Darnius	[Opal] Joaquim Mollfulleda, Minerales, Omega, 1996
Maçanet de la Selva ⓘ Can Súria quarry (Sant Ramón quarry; Guixeres quarry)	[Opal] Martí Rafel - Dr. Joan Viñals;
Osor ⓘ Osor Mines	[Opal]
Sils Massabè ⓘ Mas Sever Quarry	[Opal] Joaquim Mollfulleda, Minerales, Omega, 1996
Tarragona Priorat Bellmunt del Priorat ⓘ Joaquina primera mine	[Opal] Joan Abella i Creus (2008): Minerals I Mines De La Conca De Bellmunt Del Priorat.
ⓘ Regia mine	[Opal]
Community of Madrid ⓘ Bustarviejo	[Opal]
ⓘ Cadalso de los Vidrios	[Opal] Garcia G., Gonzalez C., Bueno A. (2004) - Cadalso de los Vidrios (Madrid), Bocamina, n° 14, pp: 12-46.
Fuenlabrada ⓘ Cerro de la Coronilla outcrop	[Opal] Geominero Museum Collection
ⓘ La Cabrera	[Opal] - González del Tánago, J., Lozano, R.P. and González del Tánago Chanrai, J. Plutón de La Cabrera. Pegmatitas graníticas y alteraciones hidrotermales. Bocamina, 2008, (21), pags. 15-85.
ⓘ La Cabrera pluton	[Opal] Tanago, J. G., Lozano, P. L., Larios, A. , La Iglesia, A. (2012) Stokesite crystals from La Cabrera, Madrid, Spain. Mineralogical Record 43:499-508
Madrid Vicálvaro ⓘ Almodóvar Hill	[Opal] Calvo, M. (2016). Minerales y Minas de España. Vol VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.
ⓘ Casa Montero	[Opal] Bustillo, M. A. y Pérez, J. L. (2005). Características diferenciales y génesis de los niveles silíceos explotados en el yacimiento arqueológico de Casa Montero (Vicálvaro, Madrid). Geogaceta, 38, 243-246.
Soto del Real ⓘ Las Calerizas	[Amber] http://www.foro-minerales.com/forum/viewtopic.php?p=133072#133072
Torrejón de Velasco ⓘ Batallones Hill	[Opal] http://www.foro-minerales.com/forum/viewtopic.php?p=133076#133076
Valdemanco ⓘ El Madroñal Quarry (La Cabrera pluton)	[Opal] - González del Tánago, J., Lozano, R.P. and González del Tánago Chanrai, J. Plutón de La Cabrera. Pegmatitas graníticas y alteraciones hidrotermales. Bocamina, 2008, (21), pags. 15-85
ⓘ Isabel Quarry (La Saludadora Quarry; La Cabrera pluton)	[Opal] Collection of the Geominero Museum of Madrid
ⓘ Los Alisos W Quarry (La Cabrera pluton)	[Opal] - González del Tánago, J., Lozano, R.P. and González del Tánago Chanrai, J. Plutón de La Cabrera. Pegmatitas graníticas y alteraciones hidrotermales. Bocamina, 2008, (21), pags. 15-85
ⓘ Peña Mojada Quarry (Los Alisos E Quarry; La Cabrera pluton)	[Opal] - González del Tánago, J., Lozano, R.P. and González del Tánago Chanrai, J. Plutón de La Cabrera. Pegmatitas graníticas y alteraciones hidrotermales. Bocamina, 2008, (21), pags. 15-85
Galicia A Coruña Santa Comba ⓘ Santa Comba Mine (Barilongo mine)	[Opal] Carlos J. Rodríguez
Ourense Viana do Bolo ⓘ Penouta mines	[Opal-A var: Opal-AN] Alfonso, P.; Hamid, S.A.; Anticoi, H.; Garcia-Valles, M.; Oliva, J.; Tomasa, O.; López-Moro, F.J.; Bascompta, M.; Llorens, T.; Castro, D.; García Polonio, F. (2020) Liberation Characteristics of Ta–Sn Ores from Penouta, NW Spain. Minerals 10, 509.
Pontevedra Ponteareas ⓘ Cillarga Quarry	[Opal] Calvo, M., Viñals, J. and Vila, F. (2009) Mineralogy of the pegmatites and miarolitic cavities in the granitic batholit of Porriño, Pontevedra, galicia, Spain. Mineral Up, (2009-1), 6-23
Porriño ⓘ Porriño quarries	[Opal] Calvo, M., Viñals, J. and Vila, F. (2009) Mineralogy of the pegmatites and miarolitic cavities in the granitic batholit of Porriño, Pontevedra, galicia, Spain. Mineral Up, (2009-1), 6-23
Murcia Cartagena La Aljorra ⓘ La Aljorra Quarries	[Opal] Sevillano, G. C., Viñals,J., Rebollar, M.C (2009): Minerales de las Vesículas de las Rocas Lamproíticas del afloramiento de La Aljorra (Murcia). Macla (11), 43-44
Sierra Minera de Cartagena-La Unión Llano del Beal ⓘ Emilia open pit (Emilia Quarry)	[Opal] FMF Forum
La Unión Sancti Spiritu ⓘ San Valentín Mine	[Opal] FMF Forum
Sierra Minera de Cartagena-La Unión ⓘ Brunita open pit (Brunita Quarry)	[Opal-A var: Opal-AN]
La Fortuna ⓘ Tomasa Mine	[Opal-A var: Opal-AN]
ⓘ Mazarrón	[Opal] Joan Rosell - RosellMinerals
Mula ⓘ Mula lamproite dike	[Opal] Fuster, J., Gastesi, P., Sagredo, J., & Fermoso, M. L. (1967). Las rocas lamproíticas del SE de España. Estudios Geológicos, 23, 35-69. Prelević, D., Foley, S. F., Romer, R., & Conticelli, S. (2008). Mediterranean Tertiary lamproites derived from multiple source components in postcollisional geodynamics. Geochimica et Cosmochimica Acta, 72(8), 2125-2156. https://doi.org/10.1016/j.gca.2008.01.029 Venturelli, G., Capedri, S., Di Battistini, G., Crawford, A., Kogarko, L. N., & Celestini, S. (1984). The ultrapotassic rocks from southeastern Spain. Lithos, 17, 37-54. https://doi.org/10.1016/0024-4937(84)90005-7
Valencian Community Alicante Agost ⓘ Sierra del Castellar	[Amber] Juan Miguel Casanova
Alicante Co. Serreta Llarga ⓘ Cemex quarries	[Amber] Casanova Honrubia, Juan Miguel & Canseco Caballé, Manuel, 2002, Minerales de la Comunidad Valenciana : 237 p. Ed. Caja de Ahorros del Mediterráneo. Alicante
Castellón Cortes de Arenoso ⓘ La Hoya deposit	[Amber] Rui Nunes 2018
Valencia Barxeta ⓘ Tozal Negro quarry	[Opal] Casanova Honrubia, Juan Miguel & Canseco Caballé, Manuel, 2002, Minerales de la Comunidad Valenciana : 237 p. Ed. Caja de Ahorros del Mediterráneo. Alicante

Sri Lanka
Southern Province Galle District ⓘ Meetiyagoda (Mitiyagoda)	[Opal] Dissanayake, C. B., Chandrajith, R. O. H. A. N. A., & Tobschall, H. J. (2000). The geology, mineralogy and rare element geochemistry of the gem deposits of Sri Lanka. BULLETIN-GEOLOGICAL SOCIETY OF FINLAND, 72(1/2), 5-20.

Sweden
Norrbotten County Jokkmokk ⓘ Ultevis	[Opal] No reference listed
Örebro County Nora Timansberg ⓘ Rökärrs Mine	[Opal] Kjell Gatedal
Skåne County Osby ⓘ Osby quarry	[Opal] Swedish Nat.Museum
Svedala ⓘ Börringe	[Amber] eg NRM 19010038
Vellinge ⓘ Skanör	[Amber] The Swedish Museum of Natural History, Bergskollegiums collection # 18572969, 18572970
Ystad ⓘ Kåseberga	[Amber] Håkan Hansson photo, id1135718.
Värmland County Filipstad Långban Ore District ⓘ Långban Mine	[Opal] Rocks & Min.: 63:456; Nysten, P., Holtstam, D. and Jonsson, E. (1999) The Långban minerals. In Långban - The mines,their minerals, geology and explorers (D. Holtstam and J. Langhof, eds.), Swedish Museum of Natural History and Raster Förlag, Stockholm & Chr. Weise Verlag, Munich, pp. 89-183.

Switzerland
Bern Interlaken-Oberhasli ⓘ Guttannen	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): Mineralienlexikon der Schweiz. Wepf (Basel), p. 291.
Oberaar lake area Triebten lake (Trübten lake) ⓘ Breccia outcrop	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): Mineralienlexikon der Schweiz. Wepf (Basel), p. 291.
Fribourg Sense Plasselb ⓘ Plasselbschlund	[Amber] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): "Mineralienlexikon der Schweiz", Wepf (Basel), p. 491
Grisons Albula Region Surses Tinizong (Tinzen) ⓘ Parsettens Alp	[Opal-A var: Opal-AN]
Surselva Region Medel (Lucmagn) Val Medel ⓘ Val Cristallina	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): Mineralienlexikon der Schweiz. Wepf (Basel), p. 291.
Ticino Bellinzona Bellinzona ⓘ Sementina	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S., and Stuker, P. (1998) Mineralienlexikon der Schweiz. Verlag Wepf & Co. AG, Basel, page 58.
Leventina Prato (Leventina) Fiesso ⓘ Lake Tremorgio	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): Mineralienlexikon der Schweiz. Wepf (Basel), p. 291.
Lugano Carona ⓘ Madonna d'Ongero	[Opal-A var: Opal-AN] Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): Mineralienlexikon der Schweiz. Wepf (Basel), p. 291.
Valais Goms Binn ⓘ Gischi glacier (incl. Gischihorn)	[Opal-A var: Opal-AN]
ⓘ Wanni glacier - Scherbadung area (Monte Cervandone)	[Opal] Schwanz, J. (1994): Das Binntal und seine Mineralien. - Hrsg. und Verlag André Gorsatt, Binn. 271 pp.
Martigny Mont Chemin mining district ⓘ Tête des Econduits	[Opal-A var: Opal-AN]
Östlich Raron Grengiols ⓘ Chummibort	[Opal] Gorsatt, A. (Ed.) (2014): Die besten Seiten des Binntals. Mineraliensuche - Alpenblumen - Ortsgeschichten. KristalloGrafik Verlag, Achberg, Deutschland, 344 pp.
ⓘ Hillehorn northeast slope	[Opal-A var: Opal-AN] Cuchet, S., van der Burgt, A. und Meisser, N. (2005): Chummibort, eine neue Fundstelle für Arsenmineralien im Binntal. Schweizer Strahler, Nr. 2, 19-29. (in German/French)
Vaud Aigle Lavey-Morcles Lavey-les-Bains ⓘ Boitses (Les Boitses)	[Opal-A var: Opal-AN] Meisser, N. (2012): La minéralogie de l'uranium dans le massif des Aiguilles Rouges. Matér. Géol. Suisse, Sér. géotech. 96, 183 p.

Syria	[Amber] Williamson, 1932. Book of Amber


Tajikistan
Sughd Mastchoh District Altyn-Topkan ore field (Zarnisor ore field) ⓘ Altyn-Topkan deposit (Altyntopkan deposit; Altyn-Topkan Mine; Zarnisor deposit; Zarnisori Shimoli deposit; Northern Zarnisor deposit)	[Opal] Badalov, S.T., Baskakov, S.P., Golovanov, I.M., Ismailov, M.I., Kasymov, A.K., Moiseeva, M.I., Musin, R.A., Smirnova, S.K. [Бадалов, С.Т., Баскаков, С.П., Голованов, И.М., Исмаилов, М.И., Касымов, А.К., Моисеева, М.И., Мусин, Р.А., и Смирнова, С.К.] (1975) Minerals of Uzbekistan. Volume I [Минералы Узбекистана. Том I]. Publishing House "Fan" of the Uzbek SSR [Издательство "Фан" УзССР], Tashkent, 444 pp. (in Russian).

Tanzania	[Opal] Gübelin, E. and Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).

Dodoma Region Chamwino District ⓘ Haneti-Itiso area	[Opal] Schmetzer, K., Berdesinski, W. Krupp, H. (1976) Grüner Opal aus Tansania. Aufschluss: 27, 381-384.
Manyara Region ⓘ Manghola	[Opal] http://www.ganoksin.com/borisat/nenam/tanzania-mines.htm
Simanjiro District ⓘ Mwajanga diggings	[Opal] John A. Jaszczak collection
Tanga Region Korogwe Rural District ⓘ Umba River (Umba Valley)	[Opal]

Thailand
Nakhon Ratchasima Province Nakhon Ratchasima District ⓘ Nakhon Ratchasima (Khorat; Korat; Nakorn Rajsima)	[Opal] C. Lemanski, Jr. (visited, collected & photographed).

Togo
Plateaux Region Mont Haïto Kpoté ⓘ Mont Haïto Ni-Co-prospect	[Opal] Wolfgang Hampel (2013)

Tunisia
ⓘ Oum el-Kecheb Mine	[Opal] Galai, H., & Sliman, F. (2019). Mineral characterization of the Oum El Khacheb phosphorites (Gafsa-Metlaoui basin; S Tunisia). Arabian Journal of Chemistry, 12(7), 1607-1614.

Turkey
Ankara Province Beypazari District ⓘ Beypazarı trona deposit	[Opal] Helvaci, C. (1998). The Beypazari trona deposit, Ankara Province, Turkey. In Proceedings of the first international soda ash conference (Vol. 2, pp. 67-103). Laramie Wyoming.
ⓘ Polatlı District	[Opal] Temel, A., Akdag, N., and Varol, E. (2010): Goldschmidt Conference Abstracts 2010.
Balikesir Province Bigadiç District ⓘ Bigadiç Mine	[Opal] Helvaci, Cahit; Alonso, Ricardo N. (2000) Borate Deposits of Turkey and Argentina; A Summary and Geological Comparison. Turkish Journal of Earth Sciences, 9, 1-27.
Faraşköy ⓘ Kurtpınarı mine	[Opal] CAHIT HELVACI & RICARDO N. ALONSO (2000) Borate Deposits of Turkey and Argentina; A Summary and Geological Comparison. Turkish Journal of Earth Sciences, Vol. 9, 2000, pp. 1-27
Sindirgi District Mumcu ⓘ Baglar Hill	[Opal] Oygür, V. (1997). Anatomy of an epithermal mineralization: Mumcu (Balikesir-Sindirgi), Inner Western Anatolia, Turkey. Mineral Research Exploration Bulletin, 119, 29-39.
Susurluk District Sultançayırı (Sultan Tschair) ⓘ Sultançayırı Mine	[Opal] CAHIT HELVACI & RICARDO N. ALONSO (2000) Borate Deposits of Turkey and Argentina; A Summary and Geological Comparison. Turkish Journal of Earth Sciences, 9:1-27.
Bursa Province Mustafakemalpaşa District ⓘ Kestelek Mine	[Opal] CAHIT HELVACI & RICARDO N. ALONSO (2000) Borate Deposits of Turkey and Argentina; A Summary and Geological Comparison. Turkish Journal of Earth Sciences, Vol. 9, 2000, pp. 1-27
Çanakkale Province Ayvacık District ⓘ Kısacık deposit (Baharlar)	[Opal] Yigit, O. (2012) A prospective sector in the Tethyan Metallogenic Belt: Geology and geochronology of mineral deposits in the Biga Peninsula, NW Turkey. Ore Geology Reviews, 46, 118-148.
Bayramiç District ⓘ Dede Dagi prospect	[Opal] Yigit, O. (2012) A prospective sector in the Tethyan Metallogenic Belt: Geology and geochronology of mineral deposits in the Biga Peninsula, NW Turkey. Ore Geology Reviews, 46, 118-148.
Çan District ⓘ Hamamtepe silica site	[Opal] Ercan, H. Ü., Ece, Ö. I., Schroeder, P. A., & Gülmez, F. (2022). Characterıstıcs and evolutıon of the etılı sılıca sınter epıthermal deposıts, çanakkale–turkey: relatıon to alkalı chlorıde vs acıd-sulfate fluıds. Ore Geology Reviews, 104726.
Lapseki District ⓘ Adatepe prospect	[Opal] Yigit, O. (2012). A prospective sector in the Tethyan Metallogenic Belt: Geology and geochronology of mineral deposits in the Biga Peninsula, NW Turkey. Ore Geology Reviews, 46, 118-148.
Diyarbakir Province Ergani District Ergani ⓘ Ergani Mine	[Opal] Akinci, O. T. (2009). Ophiolite-hosted copper and gold deposits of Southeastern Turkey: formation and relationship with seafloor hydrothermal processes. Turkish Journal of Earth Sciences, 18(4), 475-509.
Erzurum Province Aşkale District Kop Daglari ⓘ Kop Krom mine	[Opal] Mineralien Welt 2001 02 p.53
Eskişehir Province ⓘ Saricakaya District	[Opal] Ferdinando Giovine specimen
Sivrihisar District ⓘ Kaymaz Gold Project	[Opal] Yahya Çiftçi, M. Kemal Revan, Pınar Şen & Okan Zimitoğlu (2013). International Workshop on Base and Precious Metals May 20 - 27, 2013 Field Trip Guide Book May 24-27, 2013.
Izmir Province Menderes District ⓘ Gümüldür	[Opal] KARACIK, ZEKİYE; GENÇ, S. CAN; ESENLİ, FAHRİ; GÖLLER, GÜLTEKIN. (2011) he Gümüldür Fire Opal: Mode of Occurrence and Mineralogical Aspects. Turkish Journal of Earth Sciences. Jan/Feb2011, Vol. 20 Issue 1, p99-114.
Kütahya Province Gediz District Murat Dagi ⓘ Dereköy mine	[Opal] Aral, H. (1989) Antimony mineralization in the northern Murat Dagi (western Turkey). Economic Geology: 84(4): 780–787.
ⓘ Göynük mine	[Opal] Aral, H. (1989) Antimony mineralization in the northern Murat Dagi (western Turkey). Economic Geology: 84(4): 780–787.
ⓘ Nalkaya mine	[Opal] Aral, H. (1989) Antimony mineralization in the northern Murat Dagi (western Turkey). Economic Geology: 84(4): 780–787.
Pazarlar District ⓘ Şaphane alunite deposit	[Opal] Mutlu, H., Sariiz, K., and Kadir, S. (2005): Ore Geology Reviews 26, 39-50.
ⓘ Şaphane Dagi fire opal deposit	[Opal] M. Hatipoglu, N. Türk, H.B. Buzlu (2009) Gemstone Mining History and its Importance for Environmental Economics of the ùaphane Mountain Fire Opal Deposit (Yeni Karamanca-ùaphane-Kütahya) 3rd Balkan Mining Congress, BALKANMINE pp41-45
ⓘ Simav District	[Opal] Esenli, F., Kumbasar, I., Eren, R. H., & Uz, B. (2001). Characteristics of opals from Simav, Turkey. Neues Jahrbuch fur Mineralogie-Monatshefte, (3), 97-113.
ⓘ South-Eastern Anatolia Region	[Amber] various photographs

UK
ⓘ England	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Bournemouth， Christchurch and Poole ⓘ Bournemouth	[Amber] Kirejtshuk, A. G., Merkl, O., & Kernegger, F. (2008). A new species of the genus Pentaphyllus Dejean, 1821 (Coleoptera: Tenebrionidae, Diaperinae) from the Baltic amber and checklist of the fossil Tenebrionidae. Zoosyst Ross, 17, 131-137.
Cornwall ⓘ Breage	[Opal] [Specimen in the Natural History Museum, London]
Calstock Gunnislake ⓘ Hingston Down Quarry	[Opal] Weiss, S., Green, D.H., Hooper, J.J. & Elton, N. (2007): Erzgänge und "alpine " klüfte: Die Mineralien des Hingston Quarry, Calstock, Cornwall. LAPIS 32 (11), 13-25
Camborne North Roskear ⓘ North Roskear Mine	[Opal] Hall, T.M. (1868): Edward Stanford (London), 168 pp.; Collins, J.H. (1892): "A Handbook to the Mineralogy of Cornwall and Devon", 2nd ed., D. Bradford Barton Ltd. (Truro, UK), 108 pp.
South Roskear group (Pendarves Consols) ⓘ Wheal Gerry (Higher Rosewarne Mine; incl. Wheal Chance)	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.
Troon Grenville United Mines ⓘ Wheal Gine (Wheal Polgine)	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.
Carharrack Wheal Damsel United Mines ⓘ West Wheal Damsel (Wheal Spinster)	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.; Hogg, T. (1825): A Manual of Mineralogy. Polyblank Publishers (London), p. 191; Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
ⓘ Wheal Damsel	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.; Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Carn Brea Carnkie ⓘ South Wheal Basset	[Opal] Paul De Bondt collection
Gwinear-Gwithian Copperhouse Rosewarne and Herland United Mines (Rosewarne and Herland Mine; incl. Wheal Fancy; Wheal Pleasure) ⓘ Rosewarne Mine (incl. Bowling Green Mine; Wheal Royal)	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Halancoose ⓘ Rosewarne Consols	[Opal] Goley, P. and Williams R. (1995) Cornish Mineral Reference Manual. Endsleigh Publications
ⓘ Rosewarne United Mines	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.
ⓘ New Rosewarne Mine	[Opal] Reid, C., Flett, J.S., Wilkinson, B.S.N., Dixon, E.E.L., Pollard, W., and MacAlister, D.A. (1907): The Geology of the Land's End District. HMSO Publications (London), p. 114.
Hayle Great Wheal Alfred (Alfred Consols) ⓘ Wheal Alfred	[Opal] Michael W. Kieron collection
Lostwithiel ⓘ Restormel Royal Iron Mine (Trinity Mine)	[Opal] Henwood, W.J. (1843): Transactions of the Royal Geological Society of Cornwall 5, 1-386
ⓘ Wheal Maudlin (Wheal Mawdlin; Wheal Magdalen)	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Luxulyan (Luxullian) Prideaux ⓘ Lady Rashleigh Consols	[Opal] P. D. Trebilcock
Redruth ⓘ Treskerby and Chance United Mine (incl. Treskerby Mine; Wheal Chance)	[Opal] Phillips, W. (1823): An Elementary Introduction to the Knowledge of Mineralogy, 3rd ed. William Phillips (London), 535 pp.
Wheal Buller and Beauchamp ⓘ Wheal Buller	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.; Collins, J.H. (1892): "A Handbook to the Mineralogy of Cornwall and Devon", 2nd ed., D. Bradford Barton Ltd. (Truro, UK), 108 pp.
Roche Trezaise (Tresayes) ⓘ Great Wheal Prosper China Clay Pit	[Opal] Gus Horsley collection
St Columb Major Trebudannon ⓘ Wheal Trugo	[Opal] Hogg, T. (1825): A Manual of Mineralogy. Polyblank Publishers (London), p. 191; Hall, T.M. (1868): Edward Stanford (London), 168 pp.; Collins, J.H. (1871): A Handbook to the Mineralogy of Cornwall and Devon. D. Bradford Barton Ltd. (Truro, UK), 108 pp.
St Day Busveal ⓘ Cathedral Mine	[Opal] Robin Selley and Roger Eslick (2004) Cathedral Mine. BMS Newsletter 68:13-14
ⓘ Wheal Gorland	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.; Collins, J.H. (1892): "A Handbook to the Mineralogy of Cornwall and Devon", 2nd ed., D. Bradford Barton Ltd. (Truro, UK), 108 pp.
St Dennis Hendra Downs ⓘ Great Wheal Prosper China Stone Quarry	[Opal] Courtenay Smale, pers com.
ⓘ Rostowrack China Clay Pit	[Opal] P Trebilcock collection,ex M Trudgeon clay worker collection.
St Enoder Fraddon ⓘ Wheal Remfry China Clay Pit	[Opal] No reference listed
St Ives ⓘ St Ives Consols (incl. Wellesley Mine; Wheal Mary) ?	[Opal] Collins, J.H. (1892): "A Handbook to the Mineralogy of Cornwall and Devon", 2nd ed., D. Bradford Barton Ltd. (Truro, UK), pp. 108.
St Just Botallack ⓘ Botallack Mine	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.; Collins, J.H. (1892): "A Handbook to the Mineralogy of Cornwall and Devon", 2nd ed., D. Bradford Barton Ltd. (Truro, UK), 108 pp.
ⓘ Grylls Bunny	[Opal] Carne, J. (1822): Transactions of the Royal Geological Society of Cornwall 2, 290-358
Pendeen ⓘ Boscaswell Downs Mine	[Opal] Reid, C., Flett, J.S., Wilkinson, B.S.N., Dixon, E.E.L., Pollard, W., and MacAlister, D.A. (1907): The Geology of the Land's End District. HMSO Publications (London), p. 101.
Geevor Mine ⓘ Coronation Lode	[Opal] Ex .C Smith collection. Geevor geologist.
ⓘ Wheal Carne (Wheal Maitland; Wheal London)	[Opal] Carne, J. (1822): Transactions of the Royal Geological Society of Cornwall 2, 290-358
Trewellard ⓘ Spearn Consols (Wheal Spearn)	[Opal] Carne, J. (1822): Transactions of the Royal Geological Society of Cornwall 2, 290-358
St Mewan Longstone Downs ⓘ Great Longstone China Clay Pit	[Opal] P, D, Trebilcock Collection.
Trewoon ⓘ Blackpool China Clay Pit	[Opal] P, Trebilcock. Collection
St Stephen-in-Brannel Foxhole ⓘ Stenna Gwyn Mine (Stennagwyn Mine)	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Melbur ⓘ Virginia China Clay Pit	[Opal] Curtis, N.J.; Gascooke, J.R.; Johnston, M.R.; Pring, A. (2020) A Review of the Classification of Opal with Reference to Recent New Localities. Minerals 2019, 9, 299.
ⓘ Slip China Stone Quarry	[Opal] Goley, P. and Williams R. (1995) Cornish Mineral Reference Manual. Endsleigh Publications
ⓘ South Terras Mine (Resugga & Tolgarrick Mine; Union Mine; Uranium Mine)	[Opal] Alysson Rowan Collection
Treverbyn Bugle ⓘ Goonbarrow China Clay Pit	[Opal] Curtis, N.J.; Gascooke, J.R.; Johnston, M.R.; Pring, A. (2020) A Review of the Classification of Opal with Reference to Recent New Localities. Minerals 2019, 9, 299.
ⓘ Rock Hill China Clay Pit	[Opal] No reference listed
Carluddon Carclaze China Clay Pit (Baal China Clay Pit) ⓘ Carclaze Old Tin Pit	[Opal] Goley, P. and Williams R. (1995) Cornish Mineral Reference Manual. Endsleigh Publications
Stenalees ⓘ Gunheath China Clay Pit	[Opal] Barstow, R. W. (1982). Variscite from Hensbarrow china clay works, St. Austell, Cornwall. Mineralogical magazine, 46, 512.
Cumbria South Lakeland Kentmere ⓘ Kentmere	[Opal] BMS Database
Derbyshire Derbyshire Dales District ⓘ Bakewell ?	[Opal] Ford, T., A. Sarjeant & M. Smith (1993): The minerals of the Peak district of Derbyshire. UK Jour. Mines & Minerals 13, 16-55.
Eyam ⓘ Glebe Mine ?	[Opal] Ford, T., A. Sarjeant & M. Smith (1993): The minerals of the Peak district of Derbyshire. UK Jour. Mines & Minerals 13, 16-55.
Devon North Devon Bishop's Tawton ⓘ Downrew Quarry	[Opal] Alysson Rowan Collection
South Hams Shaugh Prior ⓘ Lee Moor China Clay Pit	[Opal] W. A. E. Usshee (1912) The geology of the country around Ivybridge and Modbury. Explanation of Sheet 349
Teignbridge ⓘ Lustleigh	[Opal] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
West Devon Belstone ⓘ Belstone Consols (Mid-Devon Copper Mine)	[Opal] Solly, R.H. (1888): Mineralogical Magazine 6, 202-211
Dartmoor Forest Hexworthy ⓘ Hooten Wheals (Hexworthy Mine)	[Opal] Collection Of Bernie Millington
ⓘ Wheal Katherine	[Opal] Bernie Millington collection
Greater London Kensington and Chelsea ⓘ Kensington	[Amber] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Isle of Wight Freshwater ⓘ Norton	[Amber] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
ⓘ Kent	[Amber] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
ⓘ Norfolk	[Amber] Hall, T.M. (1868): The Mineralogist's Directory. Edward Stanford (London), 168 pp.
Northern Ireland County Down Mourne Mountains ⓘ Diamond Rocks	[Opal-A var: Opal-AN] Trevor Boyd Collection
Newcastle ⓘ Lindsay's Leap	[Opal] Greg, R.P., Lettsom, W.G. (1858) Manual of the Mineralogy of Great Britain and Ireland. John Van Voorst.
Scotland Fife Raith ⓘ Chapel Quarry	[Opal] James Phemister and A. G. MacGregor (1942) Note on Datolite and Other Minerals in a Contact-Altered Limestone at Chapel Quarry, Near Kirkcaldy, Fife. Mineralogical Magazine 26:275-282.
Highland Eilean á Chèo Isle of Skye Minginish Carbost Talisker ⓘ Talisker Bay	[Opal] No reference listed
Trotternish Portree ⓘ The Storr	[Opal]
Wales Ceredigion Ceulanymaesmawr Tal-y-bont ⓘ Esgair Hir & Esgair Fraith mines (Cambrian Mine; Cardigan Consolidated Mine; Welsh Potosi Mine; Kylon Potosi Mine)	[Opal] S. Rust collection
Upper Llanfihangell-y-Creuddyn Pontrhydygroes ⓘ Frongoch Mine (Bron-y-Goch Mine; Llawynwnwch Mine)	[Opal] Rust, Steve A. (2019) Minerals of the Frongoch Mine. Published by the author, 180 pages. ISBN 978-1-9162641-0-6.

Ukraine
Crimea ⓘ Karadag Reserve (Kara-Dag)	[Opal] Volodymyr Manyuk (2008) The Problem Of Creation Of Network National Geoparks In Ukraine. in Proceeding 33 th International Geological Congress
Simferopol area Petropavlovka Village area ⓘ Petropavlovskii quarry	[Opal] A. Tischenko. Minerals of the Crimea - World of stones, 1996, #9, p. 9-18
Lviv Oblast ⓘ Klyosovskoe amber deposit	[Amber] Natural History Museum Vienna collection
Odessa Oblast Podilsk Raion ⓘ Maiskoe gold deposit (Mayske)	[Opal] Bobrov, O. B., Merkushin, I. E., Sergienko, V. M., Pogukaj, V. I., Mudrovska, I. V., Voloshyn, O. A., ... & Sivoronov, A. O. (2006, August). Object B2. Mayske gold deposit. In International Field Workshop. IAGOD
Zhytomyr Oblast ⓘ Khoroshiv Raion (Volodarsk-Volynskii)	[Opal] Lyckberg, P., Chornousenko, V. & Wilson, W. E. (2009): Volodarsk-Volynski, Zhitomir Oblast, Ukraine. Mineralogical Record, 40, 473-506.; Bailey, J. C: Formation of cryolite and other aluminofluorides: A petrologic review. Bull. geol. Soc. Denmark, vol. 29, pp. 1-45. Copenhagen, June 10th, 1980.; Bailey, J. C. (1980). Formation of cryolite and other aluminofluorides: a petrologic review. Bulletin of the Geological Society of Denmark, 29, 1-45.

USA
Alabama Cherokee Co. ⓘ Indian Mountain	[Opal] Barwood, H. (1974) Iron Phosphate Mineral Locality at Indian Mountain, Alabama. The Mineralogical Record: 5(5): p. 242.
Clay Co. ⓘ Millerville	[Opal-A var: Opal-AN] Mineralogy of Alabama Geol Surv Ala. Bull 120
Colbert Co. Waterloo ⓘ Doan Hollow Tripoli deposit	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System:U.S. Geological Survey, Reston, Virginia
Greene Co. ⓘ Pleasant Ridge	[Amber] Ransom, Jay Ellis (1974) Gems and Minerals of America pg.197
Shelby Co. Alabaster ⓘ Alabaster chert pit	[Opal] Rocks & Min. (2007) 82:235-236
Alaska Aleutians East Borough ⓘ Four Bear; PMRGX-28 Prospect	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
ⓘ Fox Islands	[Amber] Kunz, 1898. Gems & Precious Stones of N. America, p.202.
ⓘ Unnamed Occurrence (ARDF - SB010; northwest of Ramsey Bay)	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Fairbanks North Star Borough Chena River Tors Campground Trail ⓘ Chena Hot Springs (yugawaralite locality)	[Opal] Eberling, G.D., Erd, R.C., Weber, F., Beatty, L.B. (1971) New Occurrence of Yugawaralite From the Chena Hot Springs Area, Alaska. The American Mineralogist, 56(9-10), 1699-1715.
Matanuska-Susitna Borough ⓘ Matanuska Valley	[Amber] Dempsky, M. R. (2010, March). Amber Inclusions in the Paleocene/Eocene Chickaloon Formation, Matanuska Valley, Alaska. In Geological Society of America Abstracts with Programs, (Vol. 42, No. 1, p. 186).
Nome Census Area Kougarok Mining District ⓘ Andesite Creek; Lava Lake Occurrence	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Northwest Arctic Borough Fairhaven Mining District Chicago Creek ⓘ Chicago Creek Coal Mine	[Amber] Rocks & Min.: 20:481.
Southeast Fairbanks Census Area Delta River Mining District ⓘ Unnamed Occurrence (ARDF - MH109; east of lower Eureka Glacier)	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Valdez Creek Mining District ⓘ Unnamed Occurrence (ARDF - MH095; north of upper East Fork Maclaren River)	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Valdez-Cordova Census Area Chistochina Mining District ⓘ Snipe Prospect	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
ⓘ Unnamed Occurrence (ARDF - MH197; north flank of Paxson Mountain)	[Opal] U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Arizona Apache County Cane Valley Mining District Yazzie Mesa Monument No. 2 channel ⓘ Cato Sells Mine (Cato Sells Monument Mine; Cato Sells tract 1 and 2)	[Opal] Reinhardt, E.V. (1951), Reconnaissance trip to Monument Valley, USAEL, RMO o. 624; Ridge, J.D. (1968), Ore deposits of the United States 1933-1967, Vol. 1: 799-803.
ⓘ Monument No. 2 Mine	[Opal-A var: Opal-AN] Witkind, I.J. & R.E. Thaden (1963), Geology and uranium-vanadium deposits of the Monument Valley area, Apache and Navajo Cos., AZ: 123.
Concho Concho Creek ⓘ Concho Creek deposit	[Opal] Phillips, K.A. (1987), Arizona Industrial Minerals AZ Dept. of Mines and Mineral Resources Mineral Rpt. 4.; Peirce, H.W. (1969), Diatomite in mineral and water resources f Arizona, US Govt. printing office, Washignton: 337-342; Peirce, H.W. (1990), AZ Geol. Sur. Industrial Minerals card file.
Cochise County ⓘ Bisbee	[Opal-A var: Opal-AN] Rolf Luetcke
Carr Canyon ⓘ Reef Mine (Tungsten Reef Mine; Exposed Reef Mine; Sitric Mine; Reef group of claims)	[Opal-A var: Opal-AN] Eckhard D. Stuart collection
Chiricahua Mountains California Mining District (Chiricahua Mining District) ⓘ Flys Peak (Fly Peak)	[Opal] Mary Luetcke
Portal ⓘ King Ainsworth Mine group (Oregon Mine group)	[Opal] Rolf Luetcke
Cochise Mining District Black Rock group ⓘ Tungsten King Mine (Tungsten King group of claims; Tungsten Queen group of claims)	[Opal-A var: Opal-AN] Rolf Luetcke
Centurion ⓘ Centurion Mine (Lady Rose group; Alaskite group)	[Opal-A var: Opal-AN] Rolf Luetcke
Dragoon ⓘ Unnamed W-Cu prospect	[Opal] Rolf Luetcke
Curtiss ⓘ Curtis Diatomite deposit (Curtiss Diatomite deposit)	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87; MRDS database Dep. ID file #10060237, MRDS ID #TC10206.
Dos Cabezas Mountains Dos Cabezas Mining District (Two Heads Mining District) Dos Cabezas ⓘ Dos Cabezas project (Gold Prince Mine; Henry Clay Mine; Pat Price Mine; Bain Mine; Murphy Mine; Basin Mine)	[Opal] Rolf Luetcke
ⓘ La Fluorita Dulcita prospect ?	[Opal] Personally collected by bob Jackson, 2011
Middle Pass Mining District Black Diamond Peak ⓘ Festerling Mine (Elsicor Mine; Cora Mine)	[Opal] Rolf Luetcke
Gordon Camp ⓘ San Juan Mine (San Juan group; Gordon Mine; Mann adit; Sulphide adit; Silver adit)	[Opal] Rolf Luetcke
ⓘ Unnamed Cu-Ag prospect	[Opal] Rolf Luetcke
Post Ranch ⓘ Post Ranch deposit	[Opal] MRDS database Dep. ID file #10060238, MRDS ID #TC10207.
ⓘ Rustler Park	[Opal] Rolf Luetcke
ⓘ Saint David area	[Opal] Rolf Luetcke
ⓘ Opal occurrence [1]	[Opal] Rolf Luetcke Collection
Tombstone Mining District Contention-Grand Central Mine group ⓘ Contention Mine	[Opal-A var: Opal-AN] Dana 6:1093.
ⓘ Grand Central Mine	[Opal-A var: Opal-AN] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 315; Williams, S.A. (1979), Girdite, oboyerite, fairbankite, and winstanleyite, four new tellurium minerals from Tombstone, AZ, Mineralogical Magazine: 43: 453-457; Rocks & Min.:57:12.
ⓘ Empire Mine	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Gallagher Vanadium & Rare Minerals Corp Mine (Gallagher vanadium property; Bradsher Mine; Stella Mine; Vogel Mine; Buena Vista Mine)	[Opal] Rolf Luetcke
ⓘ Joe & Grand Central shafts area dump	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 171; Williams, S.A. (1981a), Choloalite, CuPb(TeO3)2·H2O, a new mineral, Mineralogical Magazine: 44: 55-57.
ⓘ Joe Mine	[Opal] Anthony, J.W., et al (1995), Mineralogy of AZ, 3rd.ed.: 211, 212-213, 356.
ⓘ Lucky Cuss Mine	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Butler, B.S., et al (1938b), Geology and ore deposits of the Tombstone district, AZ, AZ Bur. Mines Bull. 143; Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
ⓘ Montezuma Mine	[Opal] Rolf Luetcke
Turquoise Mining District (Courtland-Gleeson Mining District) Courtland Casey Hill ⓘ Last Chance Mine (1907 Mine)	[Opal] Rolf Luetcke
ⓘ Maid of Sunshine Mine	[Opal] Rolf Luetcke
Yellowstone Mining District ⓘ American Mine (American shaft; War Eagle Mine; La Vantia Mine; La Ventia Mine)	[Opal] Rolf Luetcke
Coconino County Cameron Mining District ⓘ Cameron	[Opal] Bollin, E. M., & Kerr, P. F. (1958). Uranium mineralization near Cameron, Arizona. In Guidebook of the Black Mesa Basin, northern Arizona: New Mexico Geological Society, 9th Field Conference Society Guidebook (Vol. 9, pp. 161-168).
Montezuma group of claims ⓘ Montezuma No. 2	[Opal] Scarborough, Robert B. (1981), Radioactive occurrences and uranium production in Arizona, Arizona Bureau of Geology and Mineral Technology Report for U.S. Department of Energy (Atomic Energy Commission), GJBX-143. RME-2071: 156.
ⓘ Montezuma Nos. 7A-7B-7C	[Opal] Scarborough, Robert B. (1981), Radioactive occurrences and uranium production in Arizona, Arizona Bureau of Geology and Mineral Technology Report for U.S. Department of Energy (Atomic Energy Commission), GJBX-143. RME-2071: 156.
San Franciscan volcanic field (San Francisco Peaks; San Francisco Mts) ⓘ Sunset Crater (Sunset Peak)	[Opal] Hanson, S. L., A. U. Fastner, W. B. Simmons (2008) Mineralogy of the Fumerole deposits at Sunset Crater Volcano National Monument, Northern Arizona. Rocks & Mnerals 83:6 pp 534-544.
Williams ⓘ Perrin Ranch	[Opal] Tauber, Sebastian (2015) unpublished data on site visit.
Gila County Globe-Miami Mining District Globe Hills Mining District Buffalo Gulch ⓘ Darius Mine	[Opal] MRDS database Dep. ID #10109030, MRDS ID #M002898.
Miami-Inspiration Mining District Inspiration Miami-Inspiration deposit ⓘ Inspiration Mine	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Sun, M.S. (1963), The nature of chrysocolla from Inspiration mine, AZ, Am.Min.: 48: 649-658.
ⓘ Northwestern portion of Gila County	[Opal-A var: Opal-AN] Anthony, J.W., et al (1995), Mineralogy of AZ, 3rd.ed.: 193; Granger, H.C. & R.B. Raup (1969), Geology of uranium deposits in the Dripping Spring quartzite, Gila Co., AZ, USGS PP 595.
San Carlos Skeleton Wash ⓘ Skeleton Wash deposit	[Opal] Bromfield, C.S. & A.F. Shride (1956), Mineral resources of the San Carlos Indian Reservation, AZ, USGS Bull. 1027-N: 683.
Sierra Ancha Mountains Sierra Ancha Mining District Asbestos Point (Asbestos Peak) area Warm Spring Canyon ⓘ Red Bluff Mine (Red Bluff prospect; Red Bluff claims; Claim MS 4788)	[Opal-A var: Opal-AN] Granger, H.C. & R.B. Raup (1969), Geology of uranium deposits in the Dripping Spring quartzite, Gila Co., AZ, USGS PP 595; Granger, H.C. & R.B. Raup (1959), Uranium deposits in the Dripping Spring Quartzite, Gila Co., AZ, USGS Bull. 1046-P: 457-459.
Aztec Lodge area Workman Creek area ⓘ Suckerite claims (Charles Jr. No. 1 & 2; Definitely group; Tulsa Minerals Inc. property; Uranium Corp. lease)	[Opal-A var: Opal-AN] Granger, H.C. & R.B. Raup (1959), Uranium Deposits in the Dripping Spring Quartzite, Gila Co., AZ, USGS Bull. 1046-P: 469-470.
ⓘ Easy deposit	[Opal-A var: Opal-AN] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 297; Granger, H.C. & R.B. Raup (1969), Geology of uranium deposits in the Dripping Spring quartzite, Gila Co., AZ, USGS PP 595.
Rose Creek Lodge area Workman Creek ⓘ Lost Dog claim (Lost Dog deposit; Lost Dog prospect; Lorian Mine; Melinda Mine; Via Development Co. property)	[Opal-A var: Opal-AN] Granger, H.C. & Raup (1959), Uranium deposits in the Dripping Spring Quartzite, Gila Co., AZ, USGS Bull. 1046-P: 467-468.
Workman Creek Valley Rose Creek Lodge area ⓘ Hope Mine (Hope deposit)	[Opal-A var: Opal-AN] Granger, H.C. & R.B. Raup (1959), Uranium deposits in Dripping Spring Quartzite, Gila Co., AZ, USGS Bull. 1046-P: 446, 464-466.
Graham County ⓘ Deer Creek Fire Agate Mine	[Opal] Natkaniec-Nowak, L., Dumańska-Słowik, M., Gaweł, A., Łatkiewicz, A., Kowalczyk-Szpyt, J., Wolska, A., ... & Ładoń, K. (2020). Fire agate from the Deer Creek deposit (Arizona, USA)–new insights into structure and mineralogy. Mineralogical Magazine, 84(2), 343-354.
Lone Star Mining District (Safford Mining District; Dos Pobres Mining District) Gila Valley Fort Thomas ⓘ Unnamed diatomite deposit	[Opal] MRDS database Dep. ID #10060232.
Solomon Pass ⓘ Solomon deposit (Solomonville Diatomite; Solomonville deposits)	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87; MRDS database Dep. ID #10060233.
Peridot area [Gila County] ⓘ San Carlos deposits	[Opal] MRDS database Dep. ID #10060241, MRDS ID #TC10210.
San Carlos ⓘ Skeleton Wash	[Opal] MRDS database Dep. ID #10095952, MRDS ID #TC10211.
ⓘ Triplets Wash	[Opal] MRDS database Dep. ID #10060231, MRDS ID #TC10200.
Whitlock Mountains Dry Mountain ⓘ Flat Tire group (Flat Tire diatomite deposit)	[Opal] MRDS database Dep. ID #10062190, MRDS ID #TC35492.
ⓘ White Bluffs Uranium prospect	[Opal] MRDS database Dep. ID #10209800, MAS ID #0040090360.
Slick Rock Wash ⓘ Whitlock Mines Inc. prospect (Whitlock deposit)	[Opal] MRDS database Dep. ID #10210079.
Greenlee County ⓘ Copper Mountain Mining District (Clifton-Morenci Mining District)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Reber, L.E., Jr. (1916), The mineralization at Clifton-Morenci, Econ.Geol.: 11: 528-573.
Duncan ⓘ State Route 75 opal locality	[Opal] P Cristofono collection
Morenci ⓘ Morenci Mine	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Moolick, R.T. & J.J. Durek (1966), The Morenci district, in S.R. Titley and C.L. Hicks (editors), Geology of the porphyry copper deposits, southwestern North America, Univ. AZ Press, Tucson: 221-231.
Steeple Rock Mining District (Duncan Mining District) ⓘ Duncan area Diatomite deposits	[Opal] MRDS database Dep. ID #10060236 MRDS ID #TC10205.
ⓘ Diatomite prospect	[Opal] MRDS database Dep. ID file #10161567.
La Paz County Buckskin Mountains ⓘ Cummingtonite deposit	[Opal-A var: Opal-AN] The-Vug.com Collecting Minerals of La Paz County DVD
ⓘ Heson Mine (Hesson Mine)	[Opal-A var: Opal-AN] P Cristofono collection
Santa Maria Mining District (Planet Mining District; Swansea Mining District; Bill Williams Mining District) ⓘ BCC Mines (BBC Mine; BBC claims)	[Opal-A var: Opal-AN] The-Vug.com Collecting Minerals of La Paz County DVD
Silver Mining District ⓘ Red Cloud Mine	[Opal-A var: Opal-AN] Dana 6: 1094.
Maricopa County ⓘ Lake Pleasant Mine	[Opal] MRDS file #10060235.
ⓘ Morristown	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Osborn Mining District Hummingbird Springs ⓘ Moon Anchor Mine	[Opal-A var: Opal-AN] Rolf Luetcke
Tonopah Tiger Wash ⓘ Evening Star Mine (Silver Queen Mine; Old Queen group)	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Queen of Sheba Mine (La Aguila patented claim; La Firmos Mine)	[Opal-A var: Opal-AN] Rolf Luetcke
Saddle Mountain ⓘ North slope	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Galbaith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87..
Vulture Mining District ⓘ Vulture	[Opal-A var: Opal-AN] Rolf Luetcke
Mohave County Aquarius Cliffs ⓘ Catherine and Michael claims	[Opal] Granger, H.C. & Raup, R.B. (1962), USGS Bull. 1147A, Recon. Study of Uranium Deps. in AZ: A16-A18.
Artillery Mountains Cleopatra Mining District Kimble Mining Sub-District Maggie Canyon Maggie Canyon zeolite and Mn deposit ⓘ Maggie Mine	[Opal] Mouat, M.M. (1962) Manganese oxides from the Artillery Mountains area, Arizona. American Mineralogist, 47, 744-757.
ⓘ Black Mountains	[Opal-A var: Opal-AN] Galbraith, F.W. & Brennan (1959), Minerals of AZ: 87.
Oatman Mining District Union Pass Mining District (Katherine Mining District) ⓘ Union Pass	[Opal] Galbraith, F.W. & Brennan (1959), Minerals of AZ: 87.
Lost Basin Mining District ⓘ Unnamed Au-Cu-Pb-Mo prospect [1] (USGS PP 1361 locality 482)	[Opal] Theodore, T.G., et al (1987), USGS PP 1361: 148-149 (Table 11).
Navajo County Black Mesa ⓘ Black Mesa Coal Mine	[Opal] Tauber, Sebastian (2015) unpublished data on site visit.
Pima County ⓘ Ajo Mining District	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Sun, M.S. (1961), Differential thermal analysis of shattuckite, Am.Min.: 46: 67-77.
Little Ajo Mountains Ajo ⓘ New Cornelia Mine	[Opal] Thomas, W.J. & R.B. Gibbs (1983), Famous mineral localities: The New Cornelia mine, Ajo, AZ, Min.Rec.: 14: 283-298; Gilluly, J. (1946), The Ajo mining district, Arizona, USGS PP 209: 89.
Helvetia-Rosemont Mining District ⓘ Andrada Marble Quarry	[Opal] MRDS database Dep. ID file #10060227, MRDS ID #TC10194.
Helvetia Monument Mountain ⓘ Omega Mine	[Opal] Rolf Luetcke
Tiptop Mountain Tiptop Mine group (Tiptop Camp prospects/mines) ⓘ Bulldozer Hill	[Opal-A var: Opal-AN] P Cristofono collection, 2008
Sierrita Mountains Pima Mining District (Olive Mining District; Mineral Hill Mining District; Twin Buttes Mining District) San Xavier ⓘ Mission complex	[Opal-A var: Opal-AN] No reference listed
Stevens Mountain ⓘ Copper Glance Mine (Glance Mine)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193.
Silver Bell Mountains Silver Bell Mining District Mineral Mountain ⓘ Silver Bell Mine	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Kerr, P.F. (1951), Alteration features at Silverbell, AZ, Geol. Soc. Amer. Bull.: 62: 451-480; Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Tucson Mountains Amole Mining District Tucson Mountain District Saguaro National Park ⓘ Old Yuma Mine (Yuma Mine)	[Opal-A var: Opal-AN] Rolf Luetcke
Pinal County Dudleyville area PZ Ranch area ⓘ Feldman and Winkelman Gypsum pits (Feldman Quarry; National Gypsum Co. Mine)	[Opal] MRDS database Dep. ID #10060185, MRDS ID #TC10142.
Mammoth area ⓘ M. Hererras property (Arizite Products Corp. Mine)	[Opal] Wilson, E.D. & G.H. Roseveare (1949), Arizona Nonmetallics, A Summary of Past Production and Present Operations, 2nd. Edition (revised), AZ Bur. Mines Bull. 155: 18.
Mammoth Mining District Mammoth area ⓘ San Pedro River	[Opal] Bollaert, A.R., 1962, An evaluation of the Mammoth, Arizona diatomaceous earth deposit: unpublished private report, 49p., appendices, plates: from library of Arizona Geological Survey.
Tiger St. Anthony deposit ⓘ Mammoth-Saint Anthony Mine	[Opal] Frank Karasti
Mineral Mountain Mining District Reymert Canyon ⓘ Reymert Mine	[Opal-A var: Opal-AN] Collected by C. Lemanski, Jr.
Riverside Mining District Gila River ⓘ Cochran area	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
San Pedro Mining District San Pedro River-Alder Wash confluence area San Pedro River ⓘ Eagle prospect	[Opal] MRDS database Dep. ID #10186713, MAS ID #0040230173.
Superior Mining District Superior ⓘ Picketpost Mountain	[Opal] Univ. AZ Bull. 41 (1916-17), Mineralogy of useful Minerals in AZ: 48; Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193..
Whitlock Wash area ⓘ White Cliffs Mine (Oversite claims; Arizite Mine; Nuez claims; Mammoth; Kaolin claims; Arizite Products Mine; Arizona Gypsum Mine)	[Opal] MRDS database Dep. ID #10060239, MRDS ID #TC10208.
Santa Cruz County ⓘ Jay R claim	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193.
Oro Blanco Mountains Oro Blanco Mining District (Ruby Mining District) ⓘ Arizona Blue Fire Opal claim (Scorpio claims)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193.
Redrock Mining District ⓘ Eagle deposit	[Opal] Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.
Huachuca Mountains Northwestern foothills ⓘ Lyle Creek Diatomite deposits (Huachuca deposits)	[Opal] Peirce, H.Wesley (1969), Diatomite, in USGS & Arizona Bureau of Mines & U.S. Bureau of Reclamation, Mineral and Water Resources of Arizona, Arizona Bureau of Mines Bull. 180 (USGS Bull.871): 337-342.
Redrock Canyon East of Red Rock Canyon ⓘ Precious Opal occurrence	[Opal] Lewis, W. Scott (1942), Gem collecting in California: Hobbies: 47: 116-117; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Santa Cruz village area ⓘ Grosvenor Hills	[Opal-A var: Opal-AN] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Tyndall Mining District Salero area Grosvenor Hills ⓘ Southwest of Salero	[Opal-A var: Opal-AN] Schrader, F.C. & J.M. Hill (1915), Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona, USGS Bull. 582: 361.
Yavapai County Bradshaw Mountains (Bradshaw Range) Agua Fria Mining District Mayer ⓘ Copper Queen Mine (Grey Eagle Copper Co. property; Patented claims MS 1854; 2959 & 3430)	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Agua Fria River (stream)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193, 349; Hewett, et al (1963); Galbraith, F.W. & Brennan (1959), Minerals of AZ: 87.
Castle Creek Mining District ⓘ Castle Hot Springs	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Copperopolis ⓘ Unnamed Cu prospect	[Opal] Rolf Luetcke
ⓘ Great Cross Cut prospect (Pearl adit; Johnston group; Glory Hole; Thompson Mine)	[Opal-A var: Opal-AN] Dale, V.B. (1961), Tungsten Deposits of Gila, Yavapai, and Mohave Counties, Arizona, US Bureau of Mines Information Circular 8078
Pine Grove Mining District Crown King Lane Mountain ⓘ Fat Jack Mine	[Opal] [MinRec 22:21]
Camp Verde Mining District Camp Verde ⓘ Verde River deposit	[Opal] MRDS database Dep. ID #10060244, MRDS ID #TC10214.
Eureka Mining District Bagdad ⓘ Bagdad Mine (Bagdad Copper Corp. Mine; Cyprus Bagdad Copper Co. Mine)	[Opal] Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Mayer Agua Fria River ⓘ Burmeister Mine (Bunker & Burmeister claims; Bunker claim; Black Magic Mine; Victory Manganese Mine)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 195; Hewett, D.F. & M. Fleischer (1960), Deposits of the manganese oxides, Econ.Geol.: 55: 1-55.
ⓘ Moore Wash area	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 193; Galbraith, F.W. & D.J. Brennan (1959), Minerals of AZ: 87.
Yuma County Kofa Mining District ⓘ King of Arizona Mine	[Opal-A var: Opal-AN] Former Don Miller collection
Muggins Mountains Muggins Mining District ⓘ Muggins Mountains uranium prospects	[Opal] Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geol. Sur. Br. Bull. 192, Index of Mining Properties in Yuma Co., Arizona: 164 (Table 4); US Atomic Energy Commission Prelim. Reconnaisance Reports; Arizona Bureau of Mines file data.
ⓘ Red Knob Mine (Red Knob prospect; Red Knob claims)	[Opal] Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 127, 155, 193, 411; Outerbridge, W.F., et al (1960), Weeksite, a new uranium silicate from the Thomas Range, Juab Co., UT, Am.Min.: 45: 39-52.
Arkansas ⓘ Benton County	[Opal] Arkansas Geological Survey
ⓘ Dallas County	[Opal] J. Michael Howard (2007) Mineral Species of Arkansas:Arkansas Geological Commission Bulletin 23
Garland County Indian Mountain ⓘ Smith Whetstone Quarry	[Opal] Rocks and Minerals, (1988) 63:104-125
Lake Catherine ⓘ V intrusive	[Opal] Rocks and Minerals, (1988) 63:104-125
ⓘ Malvern Minerals Company Mine	[Opal] http://www.lgsweb.org/field00g.html
Quarry Mountain (North Mountain) ⓘ Sutton Quarries	[Opal] Rocks & Min.: 21:424.
ⓘ Whittington Quarry	[Opal] Rocks & Min.: 21:424.
ⓘ Wilson Springs (Potash Sulfur Springs)	[Opal] http://www.handbookofmineralogy.org/pdfs/kingite.pdf
Union Carbide Mine ⓘ North Wilson pit	[Opal] Howard, J. Michael; Owens, Don R. (1995) Minerals of the Wilson Springs Vanadium Mines, Potash Sulphur Springs, Arkansas. Rocks & Minerals: 70(3): 154-170.
ⓘ Hot Spring County	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Magnet Cove	[Opal] Rocks and Minerals, (1976) 51:495-507
ⓘ Diamond Jo Quarry	[Opal] Henry Barwood - unpublished (2010)
Perla ⓘ Malvern clay pits	[Amber] Rocks & Min.: 63:110.
ⓘ Howard County	[Opal] Arkansas Geological Survey
ⓘ Southwest Arkansas Mercury Mining District	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S Geological Survey,Reston, Virginia
ⓘ Lonoke County	[Opal] J. Michael Howard (2007) Mineral Species of Arkansas ; Arkansas Geological Commission Bulletin 23
ⓘ Mercury District of Southwest Arkansas	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S Geological Survey,Reston, Virginia
ⓘ Montgomery County	[Opal] J. Michael Howard (2007) Mineral Species of Arkansas ; Arkansas Geological Commission Bulletin 23
Pike County ⓘ Mercury District of Southwest Arkansas	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S Geological Survey,Reston, Virginia
Murfreesboro ⓘ Crater of Diamonds State Park (Prairie Creek Lamproite)	[Opal-A var: Opal-AN] P Cristofono collection, 2007
Polk County Shady ⓘ Coon Creek Mine	[Opal] Rocks & Min.:63:118.
ⓘ Sam Avants prospects	[Opal] Rocks and Minerals, (1988) 63:104-125
Pulaski County Little Rock ⓘ Granite Mountain area	[Opal] Rocks and Minerals, (1988) 63:104-125; Rocks and Minerals, (1989) 64:314-322
ⓘ Big Rock Quarry (3M Quarry; Arch Street Pike Quarry)	[Opal] Henry Barwood - unpublished (2010)
ⓘ Saline County	[Opal] Arkansas Geological Survey
Sevier County Gillham ⓘ Antimony Bluff Mine	[Opal] Rocks & Min.:63:123; Howard(1979).
ⓘ Union County	[Opal-A var: Opal-AN] Arkansas Geological Survey
Washington County ⓘ Farmington (Engels Mills)	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
California Alpine Co. ⓘ Monitor - Mogul Mining District	[Opal] MinRec 22:29-42
Leviathan Peak ⓘ Leviathan Mine	[Opal] Pabst, Adolf (1940), Cryptocrystaline pyrite from Alpine County, California: American Mineralogist: 25: 425
Amador Co. Fiddletown Mining District (Oleta Mining District) River Pines ⓘ Chrysoprase and Moss Opal deposits	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10259764.
Pardee Mining District Sunnybrook ⓘ Custer prospect (Dooley prospect; Custer Dooley prospect)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10028081.
Volcano Mining District ⓘ Volcano	[Opal] California Journal of Mines and Geology (1954): 50(1); January, 1954: 211; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10114252.
ⓘ Unknown diamond occurrence [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10028324.
Calaveras Co. Camanche Mining District Wallace ⓘ Wallace Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10028568.
East Belt Mokelumne Hill Mining District Mokelumne Hill Chili Gulch (Chile Gulch ?) ⓘ Chili Gulch occurrences	[Opal] Browne, J.R. (1869), Report of J. Ross Browne on the mineral resources of the states and territories west of the Rocky Mountains (US Treasury Dept.), 674 pp., H.H. Bancroft and Co., San Francisco [reprint of 2]: 56; Kunz, George Frederick (1905a), Gems, jewelers’ materials, and ornamental stones of California: California Division Mines Bulletin 37, 171 pp.: 76; Lewis, W. Scott (1933), Occurrences of opal in California: Rocks & Minerals: 8: 36-37.
ⓘ Green Mountain Mine (Calaveras Crystal mine)	[Opal] Clark, William B. & Lydon, Philip A., California division of mines and geolgy (1963) MINES AND MINERAL RESOURCES OF CALAVERAS COUNTY, CALIFORNIA, county report number 2, pages 87-88.
ⓘ Rough Diamond Mine (Rough Diamond Placer Mine; Rough Diamond Crystal Mine)	[Opal] Clark, William B. & Lydon, Philip A., California division of mines and geology (1963) MINES AND MINERAL RESOURCES OF CALAVERAS COUNTY, CALIFORNIA, county report number 2, page 91
ⓘ Hexter Placer Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10109141.
French Creek Mining District Mountain Top ⓘ Dean Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10109076.
Mother Lode Belt Carson Hill Mining District (Melones Mining District) Melones Carson Hill Gold Mining Company Mines (Carson Hill Mines) ⓘ Stanislaus Mine	[Opal] Dana 7:I:206; Dana 6: 1095.
Pardee Mining District Camp Pardee ⓘ Gillam Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10284427.
Toyon ⓘ Hooten Ranch deposit	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10028681.
Colusa Co. Coast Ranges Sugarloaf ⓘ Burgett prospect	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10029530.
Sulphur Creek Mining District (Sulfur Creek Mining District; Wilbur Springs Mining District) Wilbur Springs Cherry Hill deposit ⓘ Wide Awake Mine (Buckeye Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Elgin Mine	[Opal] White, D.E. (1967) Mercury and base-metal deposits with associated thermal and mineral waters. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. Holt Reinhart and Winston, New York: 591; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 351.
ⓘ Elgin Mine area	[Opal] White, D.E. (1967) Mercury and base-metal deposits with associated thermal and mineral waters. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. Holt Reinhart and Winston, New York: 591; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
ⓘ Petray Mine (Judy Mine)	[Opal] Slowey, A.J., and Rytuba, J.J. (2008): USGS Open-File Report 08-1179
Contra Costa Co. Bayview-Montalvin ⓘ Pinole prospect (Pinole Dohrman; Pawsey; Dohrman Pawsey)	[Opal] Davis, Fenelon Francis & J.W. Vernon (1951), Mines and mineral resources of Contra Costa County, California: California Journal of Mines and Geology (Report 47): 47(4): 574, 610; Davis, Fenelon Francis and H.B. Goldman (1958) Mines and mineral resources of Contra Costa County. California Journal of Mines and Geology: 54(4): 521, 571, Pl. 5.
El Dorado Co. Mother Lode Belt East Segment Mother Lode Georgetown District Meadow Brook ⓘ Stifle claims (Stifle prospects; Stifle Memorial claim; Traverse Cr. Special Interest Area; Traverse Creek Special Interest Area)	[Opal] Len Pisciotta (2019) White grossular from near the Stifle claim, Georgetown, El Dorado County, California. Mineralogical Record 50:713-717
Salmon Falls Mining District (Flagstaff Hill area) Flagstaff Hill Pilliken Mine (Pillikin Mine; Pillikan Mine; Pilliken Chrome Mine) ⓘ Pillikin Mine area 3 (West Basin)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Steele Mine (Steel deposit)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Fresno Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Big Creek-Rush Creek Mining District ⓘ Big Creek	[Opal] Walstrom,R.E. and Leising J.F. (2005) Barium Minerals of the Sanbornite Deposits, Fresno County, California Mineralogical Record V1 No.8 p1-18.
ⓘ Esquire No. 7 claim	[Opal] Robert E. Walstrom collection
ⓘ Esquire No. 8 claim	[Opal] Robert E. Walstrom collection
ⓘ Rush Creek	[Opal] Alfors, J.T., M.C. Stinson, R.A. Matthews & A. Pabst (1965), Seven new barium minerals from eastern Fresno County, California: American Mineralogist: 50: 318, 322-324; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 464.
ⓘ Cole Spring Outcrops	[Opal] Robert E. Walstrom Collection
ⓘ Esquire No. 1 claim	[Opal] Robert E. Walstrom collection
ⓘ Forbes Property	[Opal] Robert E. Walstrom Collection
ⓘ Snow Cap Mine	[Opal] Robert E. Walstrom Collection
Fresno Mountains East of Fresno ⓘ Unnamed Opal occurrence	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Little Panoche Detention Dam ⓘ Unnamed Diatomite occurrence [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10212376.
Tumey Hills ⓘ Silver Moon claims 1; 2 and 3	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10212435.
Glenn Co. Coastal Range Red Mountain Black Diamond group ⓘ Black Diamond Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Imperial Co. Chocolate Mountains Paymaster Mining District ⓘ Midway Well	[Opal] Perry, L. E. 1961 Varied agate types and locations in California: Lapidary Journal, v. 15, no. 3, p. 308-314
ⓘ Inyo Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Coso Hot Springs Coso Hot Springs deposit ⓘ Coso Mine (Devil's Kitchen; Atlas; Lynch & Lynch; Nicol; Walley-Mickey & Wheeler)	[Opal-A var: Opal-AN] Collection of RJ Martin
ⓘ Wheeler Area Mine (Coso Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Coso Mining District	[Opal] Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 115.
Darwin Hills Darwin Mining District Darwin ⓘ Custer Mine	[Opal-A var: Opal-AN] Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
Dublin Hills Shoshone ⓘ Ash Meadows Zeolite deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Green Velvet claims (Green Velvet claim; Green Velvet group)	[Opal] Troxel, Bennie Wyatt, Stinson, M.C., and Chesterman, C.W. (1957) Uranium. California Division of Mines Bulletin 176: 672-674; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
Lake Tecopa Basin ⓘ Lake Tecopa Zeolite deposit	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10100710.
Saline Valley Badwater Springs ⓘ Unnamed Diatomite occurrence [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10114829.
Sugarloaf Mountain ⓘ Little Lake Perlite deposits (Desert Materials Corp. deposit)	[Opal] Rogers, Austin Flint (1922), A new occurrence of cristobalite in California: Journal of Geology: 30: 211-216; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 162.
ⓘ Unnamed lava flow [1]	[Opal] Pemberton, H. Earl (1983), Minerals of California: 351.
Kern Co. Blackwells Corner ⓘ Unnamed Diatomite occurrence [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10285225.
Boron ⓘ Kramer Borate deposit	[Opal] Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22(9&10): 165, 169; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
West Baker ⓘ Vanuray prospect (Amargo Bentonite deposit)	[Opal] Walker, G.W., Lovering, T.G., and Stephens, H.G. (1956), Radioactive Deposits in California: Special Report 49 of the California Division of Mines & Geology: 19; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 326.
California City ⓘ Moss Opal occurrence	[Opal] Stoddard, B.H. (1923), Gems and precious stones Mineral Resources U.S., 1920, part 2: 215-218; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
El Paso Mountains El Paso Mountains District Last Chance Canyon Silica Gem claims ⓘ Barnett Opal Mine	[Opal] Christopher N. Wentzell
ⓘ Nowak Mine (Last Chance Opal Mine; Nowak Fire Opal Mine; Cowden Mine)	[Opal] Christopher Wentzell
ⓘ Unspecified Opal occurrence [1]	[Opal] MacFall (1951), Gem Hunter's Guide, 1st ed.
Ricardo ⓘ Petrified Forest	[Opal] Dibblee, T.W., Jr. and T.E. Gay (1952) Mineral deposits of Saltdale quadrangle. California Division Mines and Geology Bulletin 160: 49-50; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282; Sinkankas, J. (1976) Gemstones of North America II. Van Nostrand Reinhold Co., New York: 58-59; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
ⓘ Red Rock Canyon prospects	[Opal] Murdoch, Joseph & Robert W. Webb (1942), Notes on some minerals from southern California, III: American Mineralogist: 27: 330; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 71; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 368-369; Tschernich, R. (1992): Zeolites of the World, 64
Mojave-Rosamond Mining District (Mojave Mining District) Rosamond ⓘ Unnamed Opal occurrence [1]	[Opal] Lewis, W. Scott (1933), Occurrences of opal in California: Rocks & Minerals: 8: 36-37; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Rademacher Mining District ⓘ Unnamed Opal-Chalcedony occurrence [1]	[Opal] Kunz, George Frederick (1900), Precious stones: Mineral Resources U.S., 1899: 54 (page = 454 ?); Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 317.
Rand Mountains Rand District (Randsburg District) Randsburg ⓘ Mabel S claim	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10076743.
Shale Hills ⓘ Unnamed Diatomite deposit [1]	[Opal] Braitwaite, R., Paar, W., and Chisholm, J., 1989, Phurcalite from Dartmoor, Southwest England,and its Identity with 'Nisaite' from Portugal, Mineralogical Magazine, 53:583-589.
ⓘ Lake Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
ⓘ East Mayacmas Mining District	[Opal] White, D.E. (1967) Mercury and base-metal deposits with associated thermal and mineral waters. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. Holt Reinhart and Winston, New York: 589; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
Castle Rock Springs ⓘ Helen Mine (Helen Mine group; Dead Broke Mine; American Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Middletown Great Western-Mirabel group ⓘ Great Western Mine (Laguna Western; Black Bart Mine; Tucker lease)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Pioneer Mine	[Opal-A var: Opal-AN] Dana 6: 1096.
Sulphur Creek Mining District (Sulfur Creek Mining District; Wilbur Springs Mining District) Clear Lake Oaks ⓘ Sulphur Bank Mine (Sulfur Bank Mine; Sulphur Bank deposits)	[Opal] Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 190; Brice, J.C. (1953), Geology of Lower Lake quadrangle, California: California Division Mines Bulletin 166: 62; White, D.E. & C.E. Roberson (1962), Sulphur Bank, California: Geological Society of America Buddington Memorial Volume: Petrologic studies: 403; Rocks & Minerals (1947): 22: 615-616.; White, D.E. (1967) Mercury and base-metal deposits with associated thermal and mineral waters. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. Holt Reinhart and Winston, New York: 579; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 215, 273, 355; Economic Geology (1988): 83: 606-618.
Lower Lake ⓘ Baker Mine	[Opal] USBM IC8252
Wilbur Springs area ⓘ Abbott Mine (Abbott Quicksilver Mine)	[Opal] Bailey, Edgar H. (1959), Froth veins, formed by immiscible hydrothermal fluids, in mercury deposits, California: Geological Society of America Bulletin 70: 661; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
ⓘ Lassen Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Red Rock ⓘ Long Valley Quarries (Lassenite Industries)	[Opal] California Division of Mines and Geology (1981), Mines & Mineral Producers Active in California during 1980, Special Publication 58; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10163240.
ⓘ Susanville	[Opal] Butler, 1995. Rockhounding California, p.158.
Westwood ⓘ Unnamed Diatomite occurrence [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10138895.
Los Angeles Co. Acton Mining District Acton Antelope Valley ⓘ Collecting Site Mine	[Opal] Oakeshott, Gordon Blaisdell (1958) Geology and mineral deposits of San Fernando quadrangle, Los Angeles County, California. California Division of Mines Bulletin 172, 147 pp.
Agoura Hills ⓘ Archstone	[Opal] MarekC field collection 2014
ⓘ Canwood St construction site 2014	[Opal] M.Chorazewicz collection
Charter Oak ⓘ Featherstone deposit (Feather-Stone Insulation Company)	[Opal] Sampson, Reid J. (1937), Mineral resources of Los Angeles County, California: California Journal of Mines and Geology, California Mining Bureau (Report 33): 33(3): 202; Gay, T.E. and Hoffman, S.R. (1954) Mines and mineral deposits of Los Angeles County, California. California Journal of Mines and Geology, California Division of Mines (Report 50): 50(3&4): No. 144, p. 664.
Kagel Canyon ⓘ Katz Diatomaceous Shale prospect	[Opal] Gay, T.E. and Hoffman, S.R. (1954) Mines and mineral deposits of Los Angeles County, California. California Journal of Mines and Geology, California Division of Mines (Report 50): 50(3&4): No. 207, p. 688.
Lang ⓘ Tick Canyon	[Opal] mineralsocal.org
Lomita ⓘ Diatomite deposit	[Opal] Merrill, Frederick James Hamilton (1916), San Diego, Imperial Counties: Calif. Min Bureau Report 14: 635-743; …(abstract): Geol. Zentralbl., Band 27: 395 (1922): 507; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Los Angeles Hollywood Hills Hollywood Cahuenga Pass Cahuenga Boulevard roadcut ⓘ Neuerberg locality 9	[Opal] Neuerberg, George Joseph (1951), Minerals of the eastern Santa Monica Mountains, Los Angeles city: American Mineralogist: 36: 156-160.
Malibu Point Dume ⓘ Point Dume deposit	[Opal] Gay, T.E. and Hoffman, S.R. (1954) Mines and mineral deposits of Los Angeles County, California. California Journal of Mines and Geology, California Division of Mines (Report 50): 50(3&4): 664.
Palmdale Hunt Canyon ⓘ Unnamed Zeolite occurrence	[Opal] Pemberton, H. Earl and Alexander, G.S. (1968) A new zeolite locality – overlooked 115 years ago. Mineral Explorer 2, 8 pp.: 7; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 353-354, 355, 373-374, 376.
Palos Verdes peninsula ⓘ Palos Verdes beach cliffs	[Opal] Cameron Holden’s collection
Rolling Hills ⓘ Unnamed Diatomaceous Earth quarry	[Opal] California Division of Mines and Geology, Mineral Information Service: California Mineral Production 1962: 16(11): 11, 13; USGS MRDS database (2005).
Rolling Hill Estates ⓘ Dicalite Mine (Walteria; Palos Verde Ranch; Dicalite Company)	[Opal] California Journal of Mines and Geology (1937): 33: 201-202; Gay, T.E. and Hoffman, S.R. (1954) Mines and mineral deposits of Los Angeles County, California. California Journal of Mines and Geology: 50: No. 143, p. 664.
Santa Catalina Island ⓘ Buffalo Springs Weather Station vicinity	[Opal] Bailey, E.H. (1941) Mineralogy, petrology and geology of Santa Catalina Island, California. Ph.D. dissertation (unpublished), Stanford University, Palo Alto, CA., 193 pages, at p.56 and p.75. Pemberton, H.E. (1983) Minerals of California; Van Nostrand Reinholt Press: 422.
ⓘ Santa Cruz offshore basin	[Opal] Fleischer, P. (1972) Sepiolite associated with Miocene diatomite, Santa Cruz basin, California. American Mineralogist: 57: 903-913; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 441.
Madera Co. Indian Springs ⓘ Unnamed Diatomite occurrence (1)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10256808.
ⓘ Marin Co.	[Opal-A var: Opal-AN] Pelletier, 1962. Mineral Species & Localities of Marin County
Mendocino Co. Cloverdale area Russian River ⓘ Rosenhahnite occurrence	[Opal] Pabst, Adolf, Gross, E.B., and Alfors, J.T. (1967) Rosenhahnite, a new hydrous calcium silicate from Mendocino County, California. American Mineralogist: 52: 336; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.; Pabst, Adolf, Gross, E.B., and Alfors, J.T. (1967) Rosenhahnite, a new hydrous calcium silicate from Mendocino County, California. American Mineralogist: 52: 336-351
ⓘ Merced Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
California Aquaduct Dos Amigos Pumping Station ⓘ Agricultural Minerals & Fertilizer Company	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10139878.
ⓘ Unnamed Diatomite deposits (1)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10207641.
ⓘ Mono Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Benton Range Chidago Mining District Banner Ridge ⓘ Morris Ameil group	[Opal] Calif Div Mines SR48 "Economic Geology of the Casa Diablo Mtn Quad CA"
ⓘ Morris claims (Morris Ameil group; Amiel group; Ameil et al claims)	[Opal-A var: Opal-AN] Lemmon, Dwight Moulton (1941b), Tungsten deposits of the Benton Range, Mono County, California: USGS Bulletin 22-S: 591; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 176, 282; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 355.
Bodie Hills Bridgeport Mining District Bridgeport ⓘ Laughlin prospect (Loughlin prospect)	[Opal] Holmes, G.H. (1965) Mercury in California. US Bureau of Mines Information Circular 8252: 176-177; Pemberton, H. Earl (1983), Minerals of California: 117.
Potato Peak ⓘ Alto prospect	[Opal] Holmes, G.H. (1965) Mercury in California. US Bureau of Mines Information Circular 8252: 176-177; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 117.
Willow Springs ⓘ Calmono Mine (Old Timer Mine)	[Opal] Holmes, Jr., G.W. (1965), Mercury in California: in: U.S. Bureau of Mines Information Circular 8252; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 117.
Monterey Co. King City ⓘ King City deposit	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 40-41.
Parkfield Mining District Parkfield ⓘ Patriquin Mine (Cholame-Parkfield Mine; Paloma Mining Company; Franciscan Mine; Pitts Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Santa Lucia Mts (Santa Lucia Range) Bradley ⓘ California Kieselguhr Company Mine	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 39; USGS MRDS database (2005).
ⓘ Great Lakes Carbon Corp. prospect	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 39-40; USGS MRDS database (2005).
ⓘ Jens deposit (1)	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 40.
ⓘ Riewerts deposit	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 40; USGS MRDS database (2005).
Bryson ⓘ Oakdale Ranch	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: No. 31, p. 123; USGS MRDS database (2005).
ⓘ Unnamed Diatomite occurrence [1]	[Opal] California Geology (1981): 185, figure 2 (September, 1981): 185, figure 2; USGS MRDS database (2005).
Del Rey Oaks ⓘ Work Ranch deposit	[Opal] Hart, E.W. (1966) Mines and mineral resources of Monterey County, California. California Division Mines and Geology County Report 5, 142 pp.: 41.
ⓘ Napa Co.	[Opal] [Clark, 1993 - "Hey's Mineral Index"]
Calistoga ⓘ Kellett Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Twin Peaks ⓘ Corona Mines (Vallejo Mines)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Calistoga Hot Springs ⓘ Cavagnaro prospect	[Opal] USGS MRDS database (2005), loc. file ID #10031657.
ⓘ Plymouth Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Knoxville area ⓘ Adams and Westendorf claims	[Opal] USGS MRDS database (2005), loc. file ID #10031632.
Knoxville Mining District ⓘ Knoxville	[Opal] Rocks&Min 11(8):117
ⓘ McLaughlin Mine (Manhattan Mine)	[Opal] Sherlock, R.L. and Lehrman, N.J. (1995), Occurrences of dendritic gold at the McLaughlin Mine. Mineralium Deposita: 30 (3-4): 323-327.
ⓘ Redington Mine (Boston Mine; Knoxville Mine; Excellsior Mine)	[Opal] Rogers, Austin Flint (1931b), Castanite, a basic ferric sulphate from Knoxville, California: American Mineralogist: 16: 397; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 273.
Oakville Mining District Oakville ⓘ Diatomite occurrence (1)	[Opal] California Geology (1981): 185, figure 2 (September, 1981); USGS MRDS database (2005), loc. file ID #10212662.
Vichy Springs ⓘ Basalt Rock Company Mine	[Opal] Weaver, C.E. (1949), Geology and Mineral Deposits of an Area North of San Francisco Bay, California: California Division of Mines Bulletin 149: 87, Pls. 4 & 6.
Nevada Co. Grass Valley Mining District Grass Valley ⓘ Hudson Bay Quartz Mine (Hudson Bay Qtz; Hudson Bay; Blue Ridge vein)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Orange Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Laguna Woods ⓘ Aliso prospect	[Opal] California Preliminary Report: 15: Pls. 4 and 1.
ⓘ Placer Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Plumas Co. Clio ⓘ Laura Quartz Mine	[Opal] Rocks & Min.: 17:412.
Riverside Co. Crestmore Crestmore quarries Sky Blue Hill ⓘ Commercial Quarry	[Opal-A var: Opal-AN] Woodford, A.O., Crippen, R.A., and Garner, K.B. (1941) Section Across Commercial Quarry, Crestmore, California. American Mineralogist: 26: 351-381 (366, 368).; Woodford, A.O. (1943), Crestmore minerals: California Division Mines Report 39: 359.; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
Jurupa Valley Jurupa Mountains ⓘ Jensen Quarry (Oak Quarry)	[Opal] MinRec 15:273-290
Mule Mts (Palo Verde Mts) Mule Mountains District (Hodges Mountain District) ⓘ Opal Hill Mine	[Opal]
San Benito Co. Goat Mountain ⓘ Clear Creek claim (Clear Creek Mine)	[Opal] Erd, R.C., Roberts, A.C., Bonardi, M., Criddle, A.J., Gabe, E.J., Le Page, Y. (1993) Edoylerite Hg2+3Cr6+O4S2 a new mineral from the Clear Creek claim San Benito County, California. The Mineralogical Record: 24: 471-475.; Lapis 19(12), 40 (1994).
Panoche ⓘ Reported Diatomite deposit [1]	[Opal] Anderson, Robert, and Robert W. Pack (1915), Geology and oil resources of the west border of the San Joaquin valley north of Coalinga, California, USGS Bulletin 603, 220 pp.: 211; USGS MRDS database (2005), loc. file ID #10285956.
Sampson Peak ⓘ North Star Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10040915.
San Bernardino Co. Black Mountain [2] ⓘ Unnamed Opal occurrence [1]	[Opal] Kunz, George Frederick (1903), Precious stones: Mineral Resources U.S., 1902: 76 (?); Baker, Charles L. (1911), Notes on the later Cenozoic history of the Mohave Desert region in southeastern California: California University Department of Geological Science Bulletin: 6: 347 (?); Sterrett, Douglas Bovard (1912), Gems and precious stones: Mineral Resources U.S., 1911, part 2: 1050; Sinkankas, J. (1959) Gemstones of North America. D. Van Nostrand Co., New York, 675 pp.: 124.
Bloomington ⓘ Henshaw Quarry	[Opal] Cooney, R.L. (1956), The mineralogy of the Jensen and Henshaw quarries near Riverside, California: Unpublished Master’s thesis, University of California at Los Angeles: 22, 34; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
Bristol Mountains Amboy area ⓘ New Method Mine	[Opal-A var: Opal-AN] Rolf Luetcke
Bullion Mts (Bullion Range) Stedman District (Ludlow; Rochester; Buckeye) Stedman ⓘ Bagdad-Chase Mine (Barstow mill; Camp Rochester; Pacific Mine; Pacific Mines; Roosevelt Consolidated Mine; Buckeye-Stedman-Bagdad Chase Mine)	[Opal] Robert E.Walstrom Collection
Cady Mountains Afton ⓘ Afton Canyon	[Opal]
ⓘ Mojave River Road	[Opal]
East Kramer Mining District East Kramer Borate area (East Kramer Colemanite area) ⓘ Saddleback Mountain	[Opal] MarekC (2018) pers. collection, Raman verified. MarekC (2018) MSSC Fieldtrip Report. Boron, Nov 10, 2018. http://www.mineralsocal.org/fieldtrip-information-reports/boron-nov-10-2018/
ⓘ Goffs	[Opal]
Lucerne Valley Limestone District Lucerne Valley ⓘ White Knob Quarry	[Opal] Howard H. J. (2011) Geology and fluorescent minerals in the White Knob Quarry Lucerne Valley, California. in Lasemi, Z., & Mikulic, D. G. (2011). The 47th Forum on the Geology of Industrial Minerals. p10
Newberry Mountains Newberry Springs ⓘ Black Raven prospect (Lankin; Newberry)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10033532.
ⓘ Opal Mountain	[Opal] Christopher N. Wentzell
ⓘ Opal Mountains Agate Field prospect (Black Mountain; Black Mtn)	[Opal] Robert C. Beste, PG (2005) A Location Guide for Rock Hounds in the United States. 3rd ed. Hobbit Press, St. Louis. 149p.
ⓘ Unnamed Opal-Perlite prospects [1]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10262516.
Robbers Mountain ⓘ Unnamed Agate-Quartz occurrence [2]	[Opal] Sanders, J. V. (1975). Microstructure and crystallinity of gem opals. American Mineralogist, 60, 749-757.; Perry, L. E. 1961 Varied agate types and locations in California: Lapidary Journal, v. 15, no. 3, p. 308-314.
ⓘ Searles Lake	[Opal] Tschernich, 1992. Zeolites of the World, p.315
Silver Lake Mining District Soda Mountains Baker Otto Mountain ⓘ Aga Mine	[Opal-A var: Opal-AN] Eckhard D. Stuart collection
Zzyzx ⓘ Blue Bell Mine	[Opal-A var: Opal-AN] Collected by Brent Thorne
ⓘ C-Site	[Opal-A var: Opal-AN] Collected by and in the collection of Alex Earl
San Diego County Aguanga Mountain Mining District (Smith Mountain Mining District) Oak Grove Aguanga Mountain ⓘ Maple Lode Mine (Maple claim)	[Opal-A var: Opal-AN] Cordova, E. M. 2009. Personal communication with S. L. Ritchie, SDMC, Feb.
Pala Mining District Pala ⓘ Tourmaline Queen Mountain (Pala Mtn; Queen Mtn)	[Opal] Jahns, Richard Henry & Wright, Lauren A. (1951), Gem and lithium-bearing pegmatites of the Pala district, San Diego County, California. California Division of Mines Special Report 7-A: p. 31.
Rincon Mining District Rincon Rincon Mountain ⓘ Victor Mine (Big Buck mine; Big Buck prospect)	[Opal-A var: Opal-AN] Rogers, A. F. 1910. Minerals From The Pegmatite Veins Of Rincon, San Diego Co., California. Columbia University School Of Mines Quarterly Journal Of Applied Science, Vol. 31 pp. 208-218.
San Francisco Co. ⓘ San Francisco	[Opal] Schlocker, J. (1974) Geology of the San Francisco North quadrangle. USGS Professional Paper 782, 109 pp.
ⓘ San Luis Obispo Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Los Osos ⓘ Ferrell deposit	[Opal] Laizure, Clyde McK (1925), San Francisco field division: California Journal of Mines and Geology, California Mining Bureau (Report 21): 21: 512; Franke, Herbert A. (1935a), Mines and mineral resources of San Luis Obispo County, California: California Division Mines (Report 31): 31(4): 419; USGS MRDS database (2005).
ⓘ Incello Company property (Thompson Reid Estate; U.S. Refractories Company)	[Opal] Laizure, Clyde McK (1925), San Francisco field division: California Journal of Mines and Geology, California Mining Bureau (Report 21): 21: 512-513; Franke, Herbert A. (1935a), Mines and mineral resources of San Luis Obispo County, California: California Division Mines (Report 31): 31(4): 419-420.
ⓘ San Luis Range Diatomite Mine	[Opal] Minobras (1973), Southern California Industrial Minerals: 91; USGS MRDS database (2005).
ⓘ Nipomo	[Opal] Lapidary Journal, 1954 Rock Hound Buyer's Guide, p. 135.
Pismo Beach ⓘ Pismo Heights Company property	[Opal] Laizure, Clyde McK (1925), San Francisco field division: California Journal of Mines and Geology, California Mining Bureau (Report 21): 21: 513; Minobras (1973), Southern California Industrial Minerals: 90.
San Luis Obispo ⓘ Unnamed diatomite deposit [1]	[Opal] Laizure, Clyde McK (1925), San Francisco field division: California Journal of Mines and Geology, California Mining Bureau (Report 21): 21: 512; USGS MRDS database (2005).
Santa Lucia Mts (Santa Lucia Range) Arroyo Grande ⓘ Unnamed diatomite deposit [2]	[Opal] Laizure, Clyde McK (1925), San Francisco field division: California Journal of Mines and Geology, California Mining Bureau (Report 21): 21: 512; USGS MRDS database (2005), loc. file ID #10286912.
Cambria-Oceanic Mining District Cambria ⓘ Oceanic Mine	[Opal] Am Min 64:3-4 pp 1026-1038
Chorro ⓘ Estrella Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Shell Beach ⓘ Los Penascos Ranch deposit (Los Pemascos Ranch deposit)	[Opal] Franke, Herbert A. (1935a), Mines and mineral resources of San Luis Obispo County, California: California Division Mines (Report 31): 31(4): 419; USGS MRDS database (2005).
ⓘ San Mateo Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Palo Alto area ⓘ Unnamed Hg occurrence [2]	[Opal] Rogers, Austin Flint (1911a), Eglestonite from San Mateo County, California: American Journal of Science, 4th. Series: 32: 48-50; Bradley, W.W. (1918), Quicksilver resources of California, with a section on metallurgy and ore dressing: California Mining Bureau. Bulletin 78: 149; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 173-174.
Santa Barbara Co. Buellton ⓘ Grefco Mine	[Opal] California Geology (1981): 185, figure 2 (September, 1981); USGS MRDS database (2005).
ⓘ Unnamed Diatomite deposits [10]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 4; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10262279.
Las Cruces ⓘ Unnamed Diatomite deposit	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10262074.
Lompoc ⓘ Dibble pit	[Opal] USGS MRDS database (2005).
ⓘ Great Lakes Carbon Corp. Mine	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; California Division of Mines (1962): Mineral Information Service: 15(2): 6; USGS MRDS database (2005).
ⓘ Johns-Manville Quarries Mine (Balaam Mine; Sunnyside Mine)	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: 77-78; USGS MRDS database (2005).
ⓘ Palos Colorados Quarry	[Opal] California Division of Mines and Geology (1990), Mines and mineral producers active in California (1988-89), California Department of Conservation, Division of Mines and Geology, Special Publication 103; USGS MRDS database (2005).
ⓘ San Miguelito Canyon Road Diatomite outcrop	[Opal] Amir Akhavan Collection
ⓘ Unnamed Diatomite deposit [13]	[Opal] Huguenin, Emile (1919), Santa Barbara, Ventura Counties: California Division Mines Report 15: 737; Mulryan, Henry (1936), Geology, mining and processing of diatomite at Lompoc, Santa Barbara County, California: A.I.M.E. Tech. Pub. 687, 30 pp.: 133; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
ⓘ Unnamed Diatomite deposit [3]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10213713.
ⓘ Unnamed Diatomite deposit [4]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10286715.
ⓘ Unnamed Diatomite deposits [6]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10116715.
ⓘ Unnamed Diatomite deposits [7]	[Opal] California Division of Mines Bulletin 186 (1966): Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10117036.
ⓘ Unnamed Diatomite quarry [11]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10286712.
Los Olivos ⓘ Unnamed Diatomite deposits [8]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 4; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10213477.
Santa Maria ⓘ Unspecified Opal occurrence [1]	[Opal] Rogers, Austin Flint (1938), Fossil termite pellets in opalized wood from Santa Maria, California: American Journal of Science, 5th. Series: 36: 389-392; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Santa Ynez ⓘ Unnamed Diatomite deposits [12]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 4.
Solvang ⓘ Unnamed Diatomite deposit [1]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 4; USGS MRDS database (2005).
Vandenberg Air Force Base ⓘ Unnamed Diatomite deposit [2]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10189485.
ⓘ Unnamed Diatomite deposit [5]	[Opal] Dibblee, T.W., Jr. (1950) Geology of southwestern Santa Barbara County, California, Point Arguello, Lompoc, Point Conception, Los Olivos, and Gaviota Quadrangles, California Division of Mines Bulletin 150: Pl. 3; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10286976.
Santa Clara Co. Black Wonder Mining District Mount Hamilton ⓘ Unnamed Zeolite occurrence [5]	[Opal] Murata, K.J. and Whiteley, K.R. (1973) Zeolites in the Miocene Brones sandstone and related formations of the central Coast Ranges, California. USGS Jour. Res.: 1: 256-257, 259; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 374.
Coyote Mining District Coyote ⓘ O'Connell Mine (Greenwalls property; O'Connell Ranch Mine; O'Connell Number 1; Greenwalt)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
San Jose Oak Hill ⓘ Hillsdale Mine (Chaboya-Hillsdale Mine; San Juan Bautista Mine; San Juan Mine; San Juan Quicksilver Mine; Sheboya Mine; Chapman Mine; Oak Hill Mine)	[Opal] Crittenden, Max D., Jr. (1951), Geology of the San Jose-Mount Hamilton area, California: California Division Mines Bulletin 157: 63; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 172; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 221.
Santa Cruz Mountains New Almaden Mining District New Almaden ⓘ Guadalupe Mine	[Opal] Rocks & Minerals (1944): 19: 346-347.
ⓘ New Almaden Mine (New Almaden Mines)	[Opal] Bradley, W.W. (1918), Quicksilver resources of California, with a section on metallurgy and ore dressing: California Mining Bureau. Bulletin 78, 389 pp.: 191.
Shasta Co. Brush Mountain ⓘ Unnamed Diatomite occurrence [3]	[Opal] Diller, J.S. (1895), Description of the Lassen Peak quadrangle, California: USGS Geol. Atlas, Lassen Peak folio (No. 15); […(abstract): Journal of Geology: 3: 974-976]; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10117079.
Burney Spring Mountain ⓘ Burney Mine	[Opal] Bradley, W.W. (1940), Thirty-sixth report of the State Mineralogist: California Division Mines Report 36: 107; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 382.
ⓘ Burney pit	[Opal] California Division of Mines and Geology (1990), Mines and mineral producers active in California (1988-89), California Department of Conservation, Division of Mines and Geology, Special Publication 103; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10256731.
ⓘ Lake Britton Quarry	[Opal] California Division of Mines and Geology (1981), Mines & Mineral Producers Active in California during 1980, Special Publication 58; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10286607.
ⓘ Mount Shasta Silica Mine (Shasta Diatomite group)	[Opal] Logan, Clarence August (1926), El Dorado, Shasta and Trinity Counties: California Mining Bureau. Report 22: 1-67, 163-166; Averill, Charles V. (1939), Mineral resources of Shasta County: California Journal of Mines and Geology, California Division of Mines (Report 35): 35(2): 128-129; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10077513, 10111066, & 10237834.
ⓘ Shasta Diatomite group (Mount Shasta Silica)	[Opal] Averill, Charles V. (1939), Mineral resources of Shasta County: California Journal of Mines and Geology, California Division of Mines (Report 35): 35(2): 128-129; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10111066 & 10237834.
ⓘ Unnamed Diatomite occurrence [1]	[Opal] California Division of Mines and Geology, Mineral Information Service (1963): 16(2); USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10116501.
Chalk Mountain ⓘ Insulator group	[Opal] Averill, Charles V. (1939), Mineral resources of Shasta County: California Journal of Mines and Geology, California Division of Mines (Report 35): 35(2): 128; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10111067 & 10286850.
Haney Mountain ⓘ Grefco Mine	[Opal] California Geology (1981): 185, figure 2 (September, 1981); USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10213865.
ⓘ Venture II Mine	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10237757.
Klamath Mountains East Shasta Copper - Zinc Mining District Heroult ⓘ Pit River Consolidated Mines (Pit River Mine)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10077528.
Lassen Volcanic National Park ⓘ Brokeoff Mountain	[Opal] Williams, Howel (1932), Geology of the Lassen Volcanic National Park, California: University of California Department of Geological Sciences Bulletin: 21: 249; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 235; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 265, 438.
ⓘ Lassen Peak	[Opal] Robert G. Lee, John H. Dilles, David A. John, Tanya L. Abela (2005) The mineralogy and origin of hydrothermally altered Quaternary volcanic rocks on the south flank of Lassen volcano, California: Interim report for USGS Mineral Resource External Research Program grant of $42,000 in FY 2005
Lookout Mountain ⓘ Unnamed Diatomite occurrence [2]	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10262263.
Shingletown ⓘ Stewart & Moore prospect	[Opal] California Journal of Mines and Geology (1928) (Report 24): 24: 166; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10077512 & 10164811.
Sierra Co. Alleghany Mining District (Forest Mining District) Alleghany ⓘ 16 to 1 Mine (Sixteen-to-One Mine; Original Sixteen-to-One Mine)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10310678.
Siskiyou Co. Copco Lake ⓘ Unnamed Diatomite deposit [1]	[Opal] California Division of Mines Bulletin 151: 59.
Dunsmuir ⓘ Unnamed Opal occurrence [1]	[Opal] MacFall, P.M. (1951) Gem Hunter's Guide (1st ed.). Science and Mathematics Publishing Company, 187 pages.
Klamath Mountains Shasta Retreat Mount Bradley ⓘ Unnamed Opal occurrence [2]	[Opal] Murdoch, Joseph (1946), Progress on revision of Bulletin 113 “Minerals of California,” with notes on some new mineral occurrences: California Division Mines Report 42: 197-198; […(abstract): Geological Society of America Bulletin: 57: 1256]: 101; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10286923.
Lava Beds National Monument ⓘ Catacombs Cave (The Catacombs)	[Opal] Swartzlow, Carl Robert & Walter David Keller (1937), Coralloidal opal: Journal of Geology: 45: 101-108; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
ⓘ Sonoma Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Coast Range Guerneville Mining District Guerneville ⓘ Great Eastern and Mount Jackson Mine (Sonoma Mine; Sonoma Quicksilver Mines; Guerneville Mine; Great Eastern Mine; Mount Jackson Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; Quicksilver resources of California: with a section on metallurgy and ore ... By Walter Wadsworth Bradley (1917)
Warm Springs Dam Skaggs Springs ⓘ Skaggs Springs Mine	[Opal] Everhart, Donald Lough (1950a), Skaggs Springs quicksilver mine, Sonoma County, California: California Journal of Mines and Geology: 46: 390; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 124, 343; American Mineralogist (2009): 94: 1325–1332.
Fetters Hot Springs ⓘ Mount Pisgah Vineyard	[Opal] Honke, Martin T., Jr. & Wm. E. Ver Planck, Jr. (1950), Mines and mineral resources of Sonoma County, California: California Journal of Mines and Geology: 46(1): 97; Trask, Parker Davies (1950) Geologic description of the manganese deposits of California. California Division of Mines Bulletin 152, 378 pp.: 282.
Glen Ellen Weise Ranch ⓘ Weise Clay pit	[Opal] Bradley, W.W. (1916a), Colusa, Glenn, Lake, Marin, Napa, Solano, Sonoma, Yolo County: California Mining Bureau. Report 14: 321; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Sonoma Mountains El Verano ⓘ Felder Mine	[Opal] Honke, Martin T., Jr. & Wm. E. Ver Planck, Jr. (1950), Mines and mineral resources of Sonoma County, California: California Journal of Mines and Geology: 46(1): 94, 97 (?); USGS MRDS database (2005).
Glen Ellen ⓘ Richter deposit	[Opal] Honke, Martin T., Jr. & Wm. E. Ver Planck, Jr. (1950), Mines and mineral resources of Sonoma County, California: California Journal of Mines and Geology: 46(1): 94.
West Mayacmas Mining District Castle Rock Springs area ⓘ Jumbo Mine (B & M Mine; Double Star Mine)	[Opal] Bailey, Edgar H. (1946), Quicksilver deposits of the western Mayacmas district, Sonoma County, California: California Journal of Mines & Geology, California Division Mines (Report 42): 42: 199-230; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
ⓘ Socrates Mine	[Opal] Bradley, W.W. (1918), Quicksilver resources of California, with a section on metallurgy and ore dressing: California Mining Bureau. Bulletin 78, 389 pp.: 191.
Cloverdale ⓘ Livermore Quicksilver Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Mark West Springs ⓘ Goodman Brothers deposit	[Opal] Honke, Martin T., Jr. & Wm. E. Ver Planck, Jr. (1950), Mines and mineral resources of Sonoma County, California: California Journal of Mines and Geology: 46(1): 94; USGS MRDS database (2005).
ⓘ The Geysers	[Opal] Vonsen, Magnus (1941) Preliminary report on minerals of The Geysers of Sonoma County, California. Mineralogist: 9: 247; Vonsen, Magnus (1946), Minerals at “The Geysers,” Sonoma County, California: California Division Mines Report 42: 291; 87-293; White, D.E. (1967) Mercury and base-metal deposits with associated thermal and mineral waters. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. Holt Reinhart and Winston, New York: 590; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356; Dunning, G. S. & Cooper, J. F. (1993): History and minerals of The Geysers Sonoma County, California. Mineralogical Record (1993): 24(5): 339-352.
Stanislaus Co. Cooperstown ⓘ Unnamed Diatomite occurrence (1)	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10166124.
Crows Landing ⓘ Simon Newman Company deposit	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10166026.
Tehama Co. Inskip Hill ⓘ Unspecified Lava tunnel	[Opal] Anderson, Charles A. (1930), Opal stalactites and stalagmites from a lava tube in northern California: American Journal of Science, 5th. Series: 20: 22-26; Anderson, Charles A. (1931b), Opal stalactites from a lava tube in northern California (abstract): Geological Society of America Bulletin: 42: 310; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 356.
Trinity Co. Coastal Range Wildhorse Peak ⓘ Red Cliff prospect	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10077858.
ⓘ Tulare Co.	[Opal] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282.
Dumtah ⓘ Van Gordon Creek Prospect	[Opal] Robert E. Walstrom Collection
Ivanhoe Venice Hills ⓘ Unnamed Semi-precious Gemstone occurrence [1]	[Opal] D. B. Sterrett (1912) Mineral Resources of the United States Calendar Year 1911. US Government Printing Office.
Tuolumne Co. Chinese Station ⓘ White Rock Mine	[Opal] Matthew Stanley Collection
East Belt Big Oak Flat Mining District Groveland ⓘ Sampson Lode prospect	[Opal] USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10111242 & 10263044.
ⓘ Ventura Co.	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Fillmore ⓘ Fillmore deposit	[Opal] Huguenin, Emile (1919), Santa Barbara, Ventura Counties: California Division Mines Report 15: 761; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 288.
Simi Valley ⓘ Northeast side of Simi Valley	[Amber] Murdoch, Joseph (1934), Amber in California: Journal of Geology: 42: 309-310; Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 63.
Thousand Oaks ⓘ Rolling Oaks Drive	[Opal] DeVito, A. N. (1992), Brookite and stilbite in the Santa Monica Mountains. Bull. Min. Soc. So. Calif.: 62(2) (Feb 1992): 7.
Colorado Archuleta County Wolf Creek Pass ⓘ Lower East Fork locality	[Opal] Hampson, A.G. (2004) Zeolites and Associated Minerals of the Wolf Creek Pass Area Mineral and Archuleta Counties Colorado. Rocks & Minerals, 79:5, 316-324.
Boulder County Boulder County Tungsten Mining District ⓘ Black Hawk No. 1 vein	[Opal] USGS Bull 583
ⓘ Clyde Mine (Lily Mine; Gale Mine; Hoosier; Western Star)	[Opal] Minerals of Colorado (1997) E.B. Eckel; U.S. Geological Survey Professional Paper 223
Chaffee County ⓘ Browns Canyon Mining District	[Opal] Ralph Van Alstine, (1969), USGS Prof. Paper 626
ⓘ Alderman deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Blue Stone Deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Chimney Hill Mine (Morgan Ranch Deposits; Manganese Hill)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Colorado - American Mine (West Vein; Trefone Adit; East Vein; American Shaft; Mill Adit; Branch or Collins Vein)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Last Chance Mine (Lower Adit; Kramer Mine; Adit No. 1; Adit No. 2)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Poncha Springs ⓘ Lloyd & Delay adit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Puzzle mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Snowflake Deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ White King Deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Buena Vista	[Opal] Yalmer Primeau Collection
ⓘ Buffalo Peaks	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
Chalk Creek District ⓘ Hortense Hot Spring	[Opal] Bull. Soc. Franç. Minéralo. Cristallo. , 1974, 97, p. 506.
ⓘ Mount Princeton Hot Spring	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Nathrop ⓘ Ruby Mountain	[Opal] USGS Bull 1716C
Poncha Pass Area ⓘ Poncha Hot Springs	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Sedalia Mining District ⓘ Sedalia Mine (Sedalia Copper Mine)	[Opal] ("Minerals of Colorado, updated & revised", by Eckel, Edwin B., 1997); U.S. Geological Survey Professional Paper 829
Turret Mining District ⓘ Ace High - Jackpot Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ American Flag Mine (Anaconda Mine; Ethel Consolidation Mine; Crete Mine; Holdredge Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Clear Creek County Idaho Springs Mining District (Virginia Mining District) ⓘ Gilson Gulch	[Opal] Minerals of Colorado (1997) E.B. Eckel
Lamartine Mining District ⓘ Columbia	[Opal] U.S. Geological Survey Professional Paper 319
ⓘ Jewelry Shop Mine (West Gold Mine; Sylvanite Mine)	[Opal] Minerals of Colorado (1997) Eckel, E. B.; U.S. Geological Survey Professional Paper 223; U.S. Geological Survey Professional Paper 319
Conejos County Manassa ⓘ King Turquoise Mine	[Opal] "Minerals of Colorado, updated & revised", p. 13, by Eckel, Edwin B., 1997
Custer County Rosita Mining District ⓘ Rosita Hills	[Opal] Minerals of Colorado (1997) E.B. Eckel
Douglas County Castle Rock Area ⓘ Castle Rock	[Opal] Minerals of Colorado (1997) E.B. Eckel
Eagle County Wolcott ⓘ Road side quarry on Hwy 131	[Opal-A var: Opal-AN] collected specimens by Alan Goldstein.
El Paso County Mount Rosa ⓘ Rosa No. 1 trench	[Opal] Minerals of Colorado (1997) E.B. Eckel
Fremont County McIntyre Hills Area ⓘ Spikebuck Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; USGS Prof. Paper 227
Tallahassee Creek Mining District ⓘ Barbara Claims	[Opal] Minerals of Colorado (1997) E.B. Eckel; USGS OFR 84-219
ⓘ Oliver Saddle Prospect	[Opal] Minerals of Colorado (1997) E.B. Eckel; USGS OFR 84-219
Garfield County Colorado River ⓘ Basalt	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
ⓘ Piceance Basin	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Grand County ⓘ Hot Sulfur Springs	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
Gunnison County ⓘ Gunnison River Gorge	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
Vulcan Mining District (Cebolla Mining District; Domingo Mining District) Vulcan ⓘ Good Hope Mine (Mammoth Good Hope Mine; Mammoth-Good Hope Mine; Mammoth Chimney Mine)	[Opal] Minerals of Colorado (1997) E.B. Eckel
White Earth Mining District (Powderhorn Mining District) ⓘ Alexite Manganese Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Hinsdale County Galena Mining District (Henson Creek Mining District) ⓘ Henson Creek-Ute Creek	[Opal] Minerals of Colorado (1997) E.B. Eckel
Park Mining District (Whitecross Mining District) ⓘ Goodwin's Creek	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
ⓘ Rio Grande River	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Slumgullion Earthflow (Slumgullion mud flow)	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Jefferson County Clear Creek Canyon ⓘ C.J.'s Cave	[Opal] Minerals of Colorado (1997) E.B. Eckel
Golden Mining District Golden ⓘ Green Mountain	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ North Table Mountain	[Opal] Rocks & Minerals 79:4
ⓘ South Table Mountain	[Opal] MinRec 19:153
Lake County Leadville ⓘ Belgian Mine	[Opal] The Oxidized Zinc Ores of Leadville Colorado, G. F. Loughlin, 1918
Breece Hill ⓘ Ibex Mine	[Opal] The Oxidized Zinc Ores of Leadville Colorado, G. F. Loughlin, 1918
Larimer County ⓘ Cache La Poudre River	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
ⓘ Specimen Mountain	[Opal] Minerals of Colorado (1997) E.B. Eckel
Mesa County McInnis Canyons National Conservation Area ⓘ Opal Hill	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Opal Hill	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Piceance Basin	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Mineral County Creede Mining District ⓘ Creede Formation	[Opal] Minerals of Colorado (1997) Eckel, E. B.
ⓘ Rio Grande River	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Trout Creek Sulfur Deposit	[Opal] Minerals of Colorado (1997) E.B. Eckel
Moffat County Douglas Mountain Mining District ⓘ Browns Park Formation	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Horse Draw	[Opal] Minerals of Colorado (1997) E.B. Eckel
Maybell Mining District Maybell Mines ⓘ Gertrude (G-pit)	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Marge Group	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ Nederland Mining District	[Opal] Minerals of Colorado (1997) E.B. Eckel
Park County South Park Antero Junction ⓘ Agate Creek	[Opal] Minerals of Colorado (1997) E.B. Eckel
ⓘ South Park salt works	[Opal] Minerals of Colorado (1997) E.B. Eckel
Rio Blanco County ⓘ Piceance Basin	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Saguache County ⓘ Del Norte Thunder Egg beds	[Opal] Rocks & Minerals (July-August, 2002)
ⓘ La Garita Creek	[Opal-A var: Opal-AN] Minerals of Colorado (1997) E.B. Eckel
San Juan County ⓘ South Mineral Creek	[Opal] Desborough, G. A., Smith, K. S., Lowers, H. A., Swayze, G. A., Hammarstrom, J. M., Diehl, S. F., Leinz, R. W. and Driscoll, R. L. (2010): Mineralogical and chemical characteristics of some natural jarosites. Geochimica et Cosmochimica Acta, 74, 1041-1056.
Summit County Montezuma Area ⓘ Red Jacket (Star of the West; Star of the West No. 2; Mohawk; Iowa)	[Opal] Minerals of Colorado (1997) E.B. Eckel
Teller County ⓘ Black Cloud Mine	[Opal] American Mineralogist (1982): 67: 184.
ⓘ Cripple Creek Mining District	[Opal] Minerals of Colorado (1997) E.B. Eckel
Bull Hill ⓘ Blue Bird Mine	[Opal] Lindgren, W. and Ransome, F.L. (1906) Geology and gold deposits of the Cripple Creek district, Colorado. United States Geological Survey Professional Paper 54: 372-373.
ⓘ Blue Bird Vein	[Opal] Rob Lavinsky (ex. Rochard Kosnar specimen)
ⓘ Orpha May	[Opal] Minerals of Colorado (1997) Eckel, E. B.
ⓘ Zenobia Mine	[Opal] Carnein, C., Bartos, P. (2005) The Cripple Creek Mining District Colorado. The Mineralogical Record: 36(2): 143-185.
ⓘ Divide	[Opal] Minerals of Colorado (1997) E.B. Eckel
Florissant (Topaz Butte) Florissant Area ⓘ Florissant Fossil Beds National Monument	[Opal] Keller, Lynn, K. (2006), Florissant Fossil Beds National Monument Geologic Resource Evaluation Report. Natural Resource Report NPS/NRPC/GRD/NRR—2006/009. National Park Service, Denver, Colorado.
ⓘ South Fork Twin Creek	[Amber] Kirejtshuk, A. G., Merkl, O., & Kernegger, F. (2008). A new species of the genus Pentaphyllus Dejean, 1821 (Coleoptera: Tenebrionidae, Diaperinae) from the Baltic amber and checklist of the fossil Tenebrionidae. Zoosyst Ross, 17, 131-137.
Weld County Stoneham ⓘ Sterling Mine	[Opal] Minerals of Colorado (1997) Eckel, E. B.
Yuma County Republican River ⓘ South Fork	[Opal] Minerals of Colorado (1997) E.B. Eckel
Connecticut Fairfield County Bethel ⓘ Biermann Quarries (Bethel quarries) and tourmaline ledge	[Opal-A var: Opal-AN] Januzzi, Ronald E. (1976), Mineral Localities Connecticut and Southeastern New York State. The Mineralogical Press, Danbury, Connecticut.
Brookfield ⓘ U. S. Route 7 Expressway (Danbury line to Iron Works District)	[Opal-A var: Opal-AN] Januzzi, Ronald E. (1994), Mineral Data Book - Western Connecticut and Environs. The Mineralogical Press, Danbury, Connecticut.
Danbury ⓘ North Street mall ?	[Opal-A var: Opal-AN] Januzzi, Ronald E. (1976): Mineral Localities of Connecticut and Southeastern New York State. The Mineralogical Press, Danbury, Connecticut: 192-201.
ⓘ Western Connecticut State College	[Opal-A var: Opal-AN] Januzzi, Ronald E. (1994): Mineral Data Book, Western Connecticut and Environs. The Mineralogical Press, Danbury, Connecticut.
Newtown Hawleyville ⓘ Sky Ridge railroad cut ?	[Opal-A var: Opal-AN] Januzzi (1976): Mineral Localities of Connecticut and Southeastern New York State
Redding (Reading) Branchville ⓘ Fillow Quarry (Branchville Quarry; Branchville Mica Mine; Smith Mine)	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Januzzi (1994) Mineral Data Book
ⓘ Ridgefield	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
ⓘ Casey Quarry (Ridgefield pegmatite)	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Trumbull Long Hill ⓘ Old Mine Park (Old Tungsten Mine)	[Opal-A var: Opal-AN] Januzzi, Ronald E. (1976): Mineral Localities of CT and Southeastern NY State. The Mineralogical Press, Danbury, Connecticut.
ⓘ Old Mine Plaza construction site	[Opal-A var: Opal-AN] field trip report, Garnet Gazette, December 2004, p 3.
Hartford County Glastonbury ⓘ Hale's Quarry	[Opal-A var: Opal-AN]
South Glastonbury ⓘ Eureka Quarries	[Opal-A var: Opal-AN] Harold Moritz collection
ⓘ Hollister prospects	[Opal-A var: Opal-AN] Betts, John. (1999): The Quarries and Minerals of the Dayton Road District, South Glastonbury, Connecticut. Rocks and Minerals. Volume 74, Number 2. pp. 110-121
ⓘ Howe Quarry (Howe #1 Quarry; Huspband Quarry)	[Opal-A var: Opal-AN] Harold Moritz collection
ⓘ Simpson Quarry (Wiarda Quarry)	[Opal-A var: Opal-AN] Betts, John. (1999): The Quarries and Minerals of the Dayton Road District, South Glastonbury, Connecticut. Rocks and Minerals. Volume 74, Number 2. pp. 110-121.
ⓘ Newington	[Opal-A var: Opal-AN] P Cristofono collection, 2008
ⓘ 2368-2384 Berlin Turnpike (Former Hartford Drive-In)	[Opal-A var: Opal-AN] P. Cristofono collection
Rocky Hill ⓘ Rocky Hill Quarry	[Opal-A var: Opal-AN] Shepard, Charles U. (1837), A Report on the Geological Survey of Connecticut. Hamlen, New Haven.
Litchfield County ⓘ Cornwall	[Opal] Shepard, Charles U. (1837), Report on the Geological Survey of Connecticut. B. L. Hamlem, New Haven.
ⓘ Mine Mountain graphite prospect	[Opal-A var: Opal-AN] Ed Force collection
Harwinton ⓘ Lead Mine Brook	[Opal-A var: Opal-AN] A. Berluti Collection
ⓘ State Routes 8 and 118 interchange	[Opal-A var: Opal-AN] Januzzi, Ronald E. and David Seaman. (1976): Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
New Milford Upper Merryall ⓘ New England Mining Company Quarry (Roebling Mine; Hewitt's Mine)	[Opal-A var: Opal-AN] Januzzi (1976): Mineral Localities of CT and Southeastern NY State
Roxbury Mine Hill (Ore Hill) ⓘ Roxbury Iron Mine (Shepaug Iron Company Mine; Shepaug Spathic Iron and Steel Company Mine)	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Thomaston Thomaston Dam ⓘ Thomaston Dam railroad cut	[Opal-A var: Opal-AN] Januzzi, Ronald E. and Seaman, David. (1976), Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut.
Torrington (Wolcottville) ⓘ Torringford	[Opal] Orcutt, Rev. Samuel. (1878), History of Torrington, Connecticut. J. Munsell, Albany: 174-179.
Woodbury ⓘ Nonnewaug River Industrial Park	[Opal-A var: Opal-AN] Mike Polletta Observation
Middlesex County ⓘ Durham	[Opal-A var: Opal-AN] Personally collected by A. Berluti in 2010
ⓘ Unnamed pegmatites	[Opal-A var: Opal-AN] Collected by A. Berluti in 2009-11
East Hampton (Chatham) ⓘ Anderson No. 1 Mica Mine (Swanson Mine; Swanson Lithia Mine; Old Lithia Mine; Chatham Lithia Mine)	[Opal-A var: Opal-AN] Jones, Robert W. (1960), Luminescent Minerals of Connecticut, a Guide to Their Properties and Locations. Fluorescent House, Branford, Connecticut.
Cobalt ⓘ Great Hill cobalt mines	[Opal-A var: Opal-AN] Januzzi (1976) Mineral Localities of Connecticut & Southeastern New York State
ⓘ Nathan Hall Quarry (Clark Hill Quarry)	[Opal-A var: Opal-AN] Field collected by Harold Moritz.
ⓘ Slocum prospect	[Opal-A var: Opal-AN] Schooner (1958 and 1961); Jones (1960)
ⓘ Worth and Selden Quarries (Victoria Quarry)	[Opal-A var: Opal-AN] Schooner (1958); Schooner (1961)
Haddam Haddam Neck ⓘ Rock Landing Quarry (Capt. Rohrback Quarry)	[Opal-A var: Opal-AN] Jones, Robert W. (1960): Luminescent Minerals of Connecticut, A Guide to Their Properties and Locations.
ⓘ Hewitt Gem Quarry (Herb's Gem Quarry; Sawmill Quarry)	[Opal-A var: Opal-AN] Kevin Czaja Collection
Higganum ⓘ Forest Ridge Road	[Opal-A var: Opal-AN] Former Don Miller collection
ⓘ Haddam Volunteer Fire Station	[Opal-A var: Opal-AN] Former Don Miller collection
ⓘ Jail Hill Road locality (Jail Hill Quarry)	[Opal-A var: Opal-AN] Kevin Czaja Collection
ⓘ John Salak Quarry	[Opal-A var: Opal-AN] Kevin Czaja Collection
Middletown White Rock Mining District ⓘ Riverside Quarry (Western Quarry)	[Opal-A var: Opal-AN] Harold Moritz collection
ⓘ White Rocks Quarry (Consolidated Quarry)	[Opal-A var: Opal-AN] Schooner (1958); Harold Moritz collection
Portland ⓘ Case Quarries	[Opal-A var: Opal-AN] Jones, Robert W. Jr., (1960), Luminescent Minerals of Connecticut, A Guide to Their Properties and Locations. Fluorescent House. Branford, Connecticut.
Collins Hill ⓘ Hale-Walker prospects	[Opal] Januzzi, 1976. Mineral Localities of Connecticut and Southeastern New York State (Taylor Assoc./Mineralogical Press)
Strickland pegmatite ⓘ Strickland Quarry	[Opal-A var: Opal-AN] Schooner, Richard. (1955): 90 Minerals from 1 Connecticut Hill. Rocks & Minerals: 30(7-8): 351-8.
ⓘ Gotta-Walden Prospect	[Opal-A var: Opal-AN] Jones, Robert W. (1960) LUMINESCENT MINERALS OF CONNECTICUT, A GUIDE TO THEIR PROPERTIES AND LOCATIONS.
ⓘ Hale Quarry (Andrews Quarry; Glastonbury Quarry)	[Opal-A var: Opal-AN] Jones, Robert W. (1960) Luminescent Minerals of Connecticut
ⓘ Pelton's Quarry	[Opal-A var: Opal-AN] Jones, Robert W. (1960): LUMINESCENT MINERALS OF CONNECTICUT,
ⓘ Walden Gem Quarry	[Opal-A var: Opal-AN] Rocks & Minerals (1970) 45:595-600
New Haven County Branford ⓘ Stony Creek Quarry (Norcross Granite Gneiss Rock Quarries; Castellucci Quarry)	[Opal-A var: Opal-AN] Harold Moritz collection
ⓘ Southbury	[Opal-A var: Opal-AN] Brace, John P. (1823), Miscellaneous Localities of Minerals. American Journal of Science: s.1, 6: 250-1.; Shepard, Charles U. (1837), A Report on the Geological Survey of Connecticut. Hamlen, New Haven.
Southford ⓘ Curtis Quarry (Southford Quarry; Southford pegmatite; Southbury rose quartz quarry; Bridgeport Woodfinishing Co. Quarry; Hulls Hill)	[Opal-A var: Opal-AN] Ryerson, Kathleen H. (1972) Rockhouns Guide to Connecticut
Waterbury ⓘ Blue Stone Quarry	[Opal-A var: Opal-AN] Visually identified at a CT museum, with vivid green fluorescence
ⓘ Delaware	[Amber] World of Amber
ⓘ District of Columbia (Washington D.C.)	[Opal] Bernstein, Lawrence (1976) Minerals of Washington D.C. and vicinity: U.S. Geological Survey: Open File Report 76-849, 183 p.
Florida Hillsborough Co. Tampa Tampa Bay ⓘ Ballast Point	[Opal] Zeitner (1968) Appalachian Gem Trails
Lake Co. ⓘ Unnamed Diatomite Deposit (MRDS - 10142925)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10191671)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10240829)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System; U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10240851)	[Opal] U.S.Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10241412)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey,Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10264633)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S Geological Survey,Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10289164)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S Geological Survey,Reston,Virginia
ⓘ Unnamed Diatomite Deposits (MRDS - 10143586)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey,Reston, Virginia
ⓘ Unnamed Diatomite Deposits (MRDS - 10167682)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey,Reston, Virginia
ⓘ Unnamed Peat Deposit (MRDS - 10167814)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
Osceola Co. ⓘ Unnamed Diatomite prospect [1]	[Opal] U.S. Geological Survey,2005,Mineral Resources Data System: U.S. Geological Survey,Reston,Virginia
Polk Co. Central Florida Phosphate Mining District (Bone Valley) Homeland ⓘ Clear Spring Mine	[Opal] Marc V. Hurst (2012) Central Florida Phosphate District. Southeastern Geological Society Field Trip Guidebook No. 57
ⓘ Homeland Mine	[Opal]
ⓘ Unnamed Diatomate Prospect (MRDS - 10288756)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10119015)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10216092)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10265198)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey,Reston, Virginia
ⓘ Unnamed Diatomite Deposit (MRDS - 10265300)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey,Reston, Virginia
ⓘ Unnamed Diatomite Prospect (MRDS - 10119005)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Prospect (MRDS - 10168107)	[Opal] U.S. Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Prospect (MRDS - 10191911)	[Opal] U.S.Geological Survey,2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
ⓘ Unnamed Diatomite Prospect (MRDS - 10241211)	[Opal] U.S. Geological Survey,2005,Mineral Resources Data System:U.S. Geological Survey, Reston, Virginia
Georgia Bartow County Cartersville Mining District ⓘ Cartersville	[Opal-A var: Opal-AN] Rocks & Min.: 64:185.
Bibb County ⓘ Pikes Peak Fuller's Earth	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Brooks County ⓘ Lot 270	[Opal] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Bulloch Co.	[Opal] Schrader, F.C., Stone, R.W., Sanford, S. (1917) Useful Minerals of the United States. United States Geological Survey, USGS Bulletin 624, 412 pages.
Burke County ⓘ Brier Creek	[Opal]
Girard District ⓘ Girard	[Opal-A var: Opal-AN] Rocks & Min.: 64:187.
ⓘ Stony Bluff	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Chattooga County	[Opal] Gems and Minerals of America- Jay Ellis Ransom-1974
Columbia County Augusta (north of) ⓘ Dan Quarry	[Opal-A var: Opal-AN] Rocks & Min.:64:190.
ⓘ DeKalb County	[Opal-A var: Opal-AN] Gems and Minerals of America- Jay Ellis Ransom-1974
Stone Mountain-Lithonia Mining District ⓘ Ethel quarry	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Flat Rock Quarry	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Hayne Quarry	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Floyd County	[Opal-A var: Opal-AN] [www.johnbetts-fineminerals.com]
Cave Spring ⓘ Asbury Mine	[Opal-A var: Opal-AN] Rocks & Min.:64:195; McCallie(1900).
ⓘ Meriwether County	[Opal] Gems and Minerals of America- Jay Ellis Ransom-1974
ⓘ Muscogee County	[Opal] Gems and Minerals of America- Jay Ellis Ransom- 1974
Rabun County Burton ⓘ Miller Asbestos Mine	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Laurel Creek complex	[Opal-A var: Opal-AN]
ⓘ Richmond County	[Opal] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Screven County	[Opal-A var: Opal-AN] Frank C. Schrader .,Ralph W. Stone and Samuel Sanford (1917) Useful Minerals of the United States : USGS Bulletin 624
ⓘ Washington County	[Opal] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
Warthen ⓘ Dick Warthen property	[Opal] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
White County Cleveland ⓘ Tesnatee Creek Bridge	[Opal-A var: Opal-AN] Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92
ⓘ Guam	[Opal] Schlanger, S. O. (1964) Petrology of the Limestones of Guam. USGS Professional Paper 403D
Hawaii Hawaii County ⓘ Unspecifed lava tubes (lava caves)	[Opal] Hon, K., Bove, D.J., Lee, L., and Thornber, C., 2009, The origin and zonation of sublimates and precipitates in active Hawaiian lava tubes: Geological Society of America Abstracts with Programs, v. 41, no. 7, p.193.
Honolulu County Oahu Island Koolau Range (Koolau caldera) Kailua ⓘ Keolu Hills	[Opal] Fujishima, K.Y. and Fan, P-F (1977) Hydrothermal mineralogy of Keolu Hills, Oahu, Hawaii. American Mineralogist, 62, 574-582.
ⓘ Idaho	[Opal] Gübelin, E. and Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).
Ada County Boise Mining District ⓘ Diatomite Occurrence (MRDS - 10089089)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Unnamed Diatomite occurrence [1]	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Unnamed Diatomite occurrence [2]	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Adams County Indian Valley Area ⓘ Diatomite Occurrence (MRDS - 10090104)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Boise County Idaho City Mining District Idaho City ⓘ Moore Creek	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Camas County Fairfield Area ⓘ Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Clark County Dubois ⓘ Highway 22 Road Cut	[Opal] Kim Strange collection
Spencer ⓘ Opal Mountain Mine	[Opal] Extra Lapis - English No. 10 Opal
ⓘ Spencer Opal Mine	[Opal]
Custer County Bay Horse Mining District Challis ⓘ Rat's Nest claim (Rat's Nest mine)	[Opal-A var: Opal-AN] John Cornish collection
ⓘ Spar Canyon	[Opal] Ream, Lanny R. 2004. Idaho Minerals, 2nd edition, Revised and Updated
ⓘ Mackay Mining District (Alder Creek Mining District; White Knob Mining District)	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Elmore County Glenns Ferry Area ⓘ Diatomite Deposit (MRDS - 10070133)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Diatomite Deposit (MRDS - 10070134)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Diatomite Deposit (MRDS - 10093442)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
King Hill Area ⓘ Diatomite Deposit (MRDS - 10089070)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Diatomite Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Gem County Cascade Area ⓘ Diatomite Occurrence (MRDS - 10070230)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Emmett ⓘ Squaw Butte	[Opal] The Mineralogist, v. 4, no. 1. p. 15, 15, 54.
Idaho County ⓘ Freedom	[Opal] C. Lemanski, Jr. (re-entry lost Mindat data).
Riggins ⓘ Squaw Creek	[Opal] Ream, Lanny R. 2004. Idaho Minerals, 2nd edition, Revised and Updated; American Mineralogist, Volume 67, pages 799-803, 1982
Kootenai County ⓘ Setters	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Latah County ⓘ Kendrick	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
ⓘ Moscow	[Opal] The Moscow Opal Mines 1890 to 1893 (The First Commercial Opal Mines in the United States), Ron Brockett, 1975
ⓘ Whelan	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Lemhi County Blackbird Mining District ⓘ Cutler Opal Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Blue Grouse Opal Mine	[Opal] Christopher Wentzell collection (2020) and personally verified on site (2020)
ⓘ Panther Creek	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Salmon ⓘ Idaho Blue Mine	[Opal] Extra Lapis - English No. 10 Opal
Lincoln County ⓘ Clover Creek	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Nez Perce County ⓘ Lewiston	[Opal] Dake, 156. NW Gem Trails, 2nd ed.
ⓘ Owyhee County	[Opal] Robert C. Beste, PG (2005) A Location Guide for Rock Hounds in the United States. 3rd ed. Hobbit Press, St. Louis. 149p.
ⓘ Bruneau Jasper (Bruneau Canyon 1-5; Bruneau Group Jasper)	[Opal] USGS Bulletin 1720b
ⓘ Enterprise	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
French Mining District ⓘ Diatomite Mine (Bates Creek)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Lucky Boy Group	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Marsing Area ⓘ Pumice Occurrence (MRDS - 10070280)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Opaline	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
Reynolds Area ⓘ Diatomite Occurrence (MRDS - 10106007)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Riddle Area ⓘ Diatomite Occurrence (MRDS - 10078458)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Rough Mountain Mining District ⓘ Pumicite Deposit (MRDS - 10089547)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Twin Falls County Buhl Area ⓘ Ray Banbury Diatomite Deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Valley County Big Creek Mining District ⓘ Bear Trap Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Ketchum Claim	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ W. K. No. 1 Claim	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Marble Creek Mining District ⓘ Grays Peak Opal Deposit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Monumental Creek Mining District ⓘ Monument Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Redridge Group Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Washington County Monroe Mining District ⓘ Diatomite Occurrence (MRDS - 10078450)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Weiser Mining District ⓘ Diatomite Occurrence (MRDS - 10093747)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Helen Zucker Prospect (Zucker Property; Parker Group)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Idaho Almaden Mine (Nutmeg; U.S.A. Anna; Almaden; Almaden Project)	[Opal] R&M 70:4 pp 242-263; USGS Bull 1042D
ⓘ Virginia L. Claims (Raft Creek Cinnabar; Lackey Mine)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Weiser ⓘ Diatomite Mine (MRDS - 10070229)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Illinois ⓘ Alexander Co.	[Opal] Dake, Fleener & Wilson, 1938. Quartz Family Minerals
ⓘ Union Co.	[Opal] Dake, Fleener & Wilson, 1938. Quartz Family Minerals
Indiana Henry County ⓘ New Albany shale	[Opal] Erd, R. C. and S.S. Greenburg (1960) Minerals of Indiana. Indiana Geological Survey Bulletin 18 73pp
ⓘ Perry County	[Opal] Erd, R. C. and S.S. Greenburg (1960) Minerals of Indiana. Indiana Geological Survey Bulletin 18 73pp
Kansas ⓘ Clark Co.	[Opal] Buchanan ,Rex (1986) Kansas Rocks and Minerals ; Kansas Geological Survey Educational Series # 2
ⓘ Ellis Co.	[Opal] Buchanan , Rex (1986) Kansa Rocks and Minerals ; Kansas Geological Survey Educational Series # 2
ⓘ Ellsworth Co.	[Amber] www.emporia.edu/earthsci/amber/geograph.htm
ⓘ Smoky Hill River amber locality	[Amber] C. Lemanski, Jr. (re-entry lost Mindat data).
ⓘ Logan Co.	[Opal] Buchanan ,Rex (1986) Kansas Rocks and Minerals ; Kansas Geological Survey Educational Series # 2
ⓘ Ness Co.	[Opal] Buchanan ,Rex (1986) Kansas Rocks and Minerals ; Kansas Geological Survey Educational Series # 2
ⓘ Rawlins Co.	[Opal] Buchanan, Rex (1986) Kansas Rocks and Minerals ; Kansas Geological Survey Educational Series # 2
ⓘ Wallace Co.	[Opal] Ransom, 1974. Gems and Minerals of America
ⓘ Kentucky	[Opal] Anderson (1994) Kentucky Geol. Survey Ser. XI Spec. Pub 20
Louisiana Catahoula Parish ⓘ Harrisonburg	[Opal] Earth Treasures Vol 4, Allan W. Eckert, 1987
Ouachita Parish ⓘ West Monroe	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
Vernon Parish ⓘ Hidden Fire Opal Mine (Louisiana Opal Exchange Mine)	[Opal] R&M 69:3 pp 156-162
Maine Androscoggin County Auburn East Mount Apatite Mining District ⓘ Maine Feldspar Quarry	[Opal-A var: Opal-AN] Bill Bunn
Cumberland County Baldwin West Baldwin ⓘ Estes Quarry	[Opal-A var: Opal-AN] No reference listed
Casco ⓘ Heath Quarry	[Opal-A var: Opal-AN] P Cristofono collection
ⓘ Freeport	[Opal-A var: Opal-AN] King & Foord, 1994. Mineralogy of Maine, V. 1.
Knox County Warren ⓘ Starrett Quarries	[Opal] No reference listed
Oxford County Albany ⓘ Donahue Quarry (Donahue Prospect)	[Opal] King, V. (ed.), 2009, Maine feldspar, Families, and Feuds.
ⓘ Songo Pond Quarry (Kimball Ledge Quarry)	[Opal-A var: Opal-AN] "Maine Mineral Localities, 3rd Ed." by Thompson, W.B., ey.al., 1998
Buckfield ⓘ Bennett Quarry	[Opal-A var: Opal-AN] www.geocities.com/~stuarts1031/fluorescent4.html
Greenwood ⓘ Heikkinen Quarry	[Opal-A var: Opal-AN] "Maine Mineral Localities, 3rd Ed." by Thompson, W.B., et.al., 1998
Uncle Tom Mountain ⓘ Emmons Quarry	[Opal] Falster, A. U., Simmons, W. B., Webber, K. L., Dallaire, D. A., Nizamoff, J. W., & Sprague, R. A. (2019). The Emmons Pegmatite, Greenwood, Oxford County, Maine. Rocks & Minerals, 94(6), 498-519.
Newry ⓘ Bell pit	[Opal-A var: Opal-AN] Harold Moritz collection
ⓘ Crooker Gem Pegmatite Quarries	[Opal-A var: Opal-AN] King, V. and Foord, E., 1994, Mineralogy of Maine, V. 1; King, V. (ed.), 2000, Mineralogy of Maine, V. 2, with updates by Van King
ⓘ Dunton Gem Quarry	[Opal-A var: Opal-AN] King, V. and Foord, E., 1994, Mineralogy of Maine, V. 1; King, V. (ed), 2000, Mineralogy of Maine, V. 2.
ⓘ Rose Quartz crystal locality (Pegmatite 24)	[Opal-A var: Opal-AN] King, V. and Foord, E., 1994, Mineralogy of Maine, v. 1; King, V, 2006, Minerals of Halls Ridge and Plumbago-Puzzle Mountain, Newry, Oxford County, Maine, Mineral News, v. 22 (6), p. 1-3.
Paris ⓘ Mount Mica Quarry	[Opal-A var: Opal-AN] King, V. T. and Foord, E. E., 1994, Mineralogy of Maine, Descriptive Mineralogy, volume 1, Maine Geological Survey, Augusta, Maine, USA, pp. 418 + 88 plates.
ⓘ Ryerson Hill Quarries	[Opal-A var: Opal-AN]
Peru ⓘ Perry Petalite prospect	[Opal-A var: Opal-AN] Dionne, Dick & Birtic, Cal & Jacobson, Mark. (2014) The Perry petalite prospect of Peru, Maine.. Mineral News. 30. 6,8,9,11,13.
Rumford ⓘ Black Mountain Quarry	[Opal-A var: Opal-AN] No reference listed
Stoneham ⓘ Lord Hill Quarry (Lord Hill Mine)	[Opal-A var: Opal-AN] A.Mathauser collection
Sagadahoc County Topsham ⓘ Undivided Quarry	[Opal-A var: Opal-AN] Rocks & Min.: 62:413.
ⓘ William Willes #1 Quarry	[Opal-A var: Opal-AN] Van King
ⓘ Yedlin Locality	[Opal-A var: Opal-AN] "Maine Mineral Localities, 3rd Ed." by Thompson, W.B., et.al., 1998
Maryland Anne Arundel Co. Arnold Magothy River ⓘ Cape Sable	[Amber] Kunz,1892. Gems & Precious Stones of N. America, p.199.; D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
ⓘ Garey Ore Bank	[Opal] Jat Thompson Collection
Baltimore Co. Bare Hills ⓘ Bare Hills Serpentine Quarry East	[Opal] Ostrander, C. W. & W. E. Price (1940) Minerals of Maryland: Natural History Society of Maryland, 27p.
ⓘ Unnamed Chromite prospects	[Opal] Ostrander, C. W. & W. E. Price (1940) Minerals of Maryland: Natural History Society of Maryland, 297p.
Delight ⓘ Calhoun Mine	[Opal] Pearre, N. & A. V. Heyl (1960) Mineral deposits in serpentine rocks of the Piedmont Upland, Maryland, Pennsylvania and Delaware: U. S. Geological Survey: Bulletin 1082K: 707-833.
Soldiers' Delight ridge ⓘ Delight Quarry (Soldier's Delight Quarry; Dyer Quarry)	[Opal] Rocks & Min.:11:111; 19:148.
Windsor Mill ⓘ Lord Baltimore Drive Quartz occurrence area	[Opal] Jat Thompson
Calvert Co. ⓘ Old Greensand-Diatomaceous Earth Pit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Cecil Co. State Line Mining District Pilot ⓘ Wiant's Quarry (Weiant Quarry)	[Opal] Ostrander, C. W. & W. E. Price (1940) Minerals of Maryland: Natural History Society of Maryland , 92 p.
Harford Co. Cardiff ⓘ Maryland Green Marble Corporation Quarry (Cardiff Serpentine Quarry)	[Opal-A var: Opal-AN] Minerals of Maryland (1940) Charles Ostrander and Walter E. Price, Jr., Natural History Society of Maryland. p. 56; Ostrander, C. W. & W. E. Price (1940) Minerals of Maryland: Natural History Society of Maryland , 92 p.
Montgomery Co. Rockville ⓘ Hunting Hill Quarry	[Opal] Bernstein, Lawrence R. (1980) Minerals of the Washington, D.C. area. Maryland Geological Survey Educational Series 5, 148 pages.
Silver Spring ⓘ Paint Branch	[Opal] Bernstein, Lawrence (1980) Minerals of the Washington D. C. area: Maryland Geological Survey Educational Series 5, 148 pages.
ⓘ White Oak	[Opal-A var: Opal-AN] Cordua, Bill (1969) Mineralogy of a newly exposed granite near White Oaks, MD: Rocks and Minerals: 44 (2): 114-115.
ⓘ Massachusetts	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Berkshire County ⓘ Florida	[Opal-A var: Opal-AN] Gleba, 1978. Mass. Mineral & Fossil Localities
Dukes County Martha's Vineyard Aquinnah ⓘ Gay Head Cliffs	[Amber] Robinson, Samuel (1825): A Catalogue of American Minerals, with Their Localities, p.49.; D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
Essex County ⓘ Boxford	[Opal] Sears, John Henry (1905): The Physical Geography, Geology, Mineralogy and Paleontology of Essex County
ⓘ Danvers	[Opal] Sears, John Henry (1905): The Physical Geography, Geology, Mineralogy and Paleontology of Essex County
ⓘ Gloucester	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
ⓘ Blackburn Circle locality	[Opal-A var: Opal-AN] P Cristofono collection , 2009
ⓘ Railcut Hill	[Opal-A var: Opal-AN] P. Cristofono collection 2011
ⓘ State Route 128 road cut/Cherry Hill area	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Newbury ⓘ Devil's Basin	[Opal-A var: Opal-AN] P. Cristofono collection 2011
North Andover ⓘ Route 114 calc-silicate locality	[Opal-A var: Opal-AN] P Cristofono collection , 2009
ⓘ Salem	[Opal-A var: Opal-AN] P Cristofono collection , 2009
Franklin County Deerfield ⓘ Cheapside Quarry (East Deerfield Quarry; Trew Corp. Quarry)	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities; Emerson, B. K (1882) The Deerfield Dyke and its minerals. American Journal of Science 3rd series XXIV:270-278,349-359.
ⓘ Leverett	[Opal-A var: Opal-AN] Emerson, B. K. (1895): A Mineralogical Lexicon of Franklin, Hampshire, and Hampden Counties, Massachusetts (USGS Bulletin 126).
ⓘ East Mine	[Opal-A var: Opal-AN] Emerson, B. K. (1895): A Mineralogical Lexicon of Franklin, Hampshire, and Hampden Counties, Massachusetts (USGS Bulletin 126).
Hampden County Monson ⓘ Monson quarries (Flynt quarries)	[Opal-A var: Opal-AN] Emerson, B. K. (1895): A Mineralogical Lexicon of Franklin, Hampshire, and Hampden Counties, Massachusetts (USGS Bulletin 126).
Hampshire County Easthampton ⓘ Loudville Lead Mines (Manhan Lead-Silver Mine; Southampton Lead Mine; Northampton Lead Mine)	[Opal] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Granby ⓘ Ondrick Quarry	[Opal-A var: Opal-AN] P Cristofono collection
ⓘ Middlesex County	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Ashland ⓘ Aggregate Industries Quarry (Bayer-Mingolla Quarry; Trimount Quarry)	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Dracut ⓘ PJ Keating Quarry (Dracut Quarry; Condon Quarry; Essex Bituminous)	[Opal-A var: Opal-AN] P. Cristofono collection, 2013
Holliston ⓘ Miller Hill Quarry (Jursek's Crushstone Quarry)	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Hudson ⓘ Route 62 locality (Potash Hill)	[Opal-A var: Opal-AN] P Cristofono collection 2010
ⓘ Malden	[Opal] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Marlborough ⓘ Marlborough Junction locality	[Opal-A var: Opal-AN] P Cristofono collection, 2006
ⓘ Waltham	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Weston ⓘ Massachusetts Broken Stone Co. quarries (Weston Quarry; Stony Brook Quarry)	[Opal-A var: Opal-AN] Gleba, P.P. (1978) Massachusetts Mineral and Fossil Localities. Krueger Enterprises, Cambridge, Massachusetts, 117 pages plus maps.
Woburn ⓘ Blueberry Mountain Quarry (Blueberry Hill)	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of Connecticut and Southeastern New York State (Taylor Assoc./Mineralogical Press). Chapter: "Massachusetts Mineral Localities," p206; Rocks & Min.: 21:75.
Nantucket County ⓘ Nantucket	[Amber] Robinson, Samuel (1825): A Catalogue of American Minerals, with Their Localities, p. 62. ; D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
Norfolk County Wrentham ⓘ Aggregate Industries Quarry (Wrentham Quarry; Simeone Quarry)	[Opal] No reference listed
Suffolk County Boston West Roxbury ⓘ West Roxbury Crushed Stone Quarry (West Roxbury Trap Rock Co. Quarry; Grove St. Quarry)	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Worcester County Bolton ⓘ Bolton Lime Quarries (Bolton Quarry; Whitcomb Quarry; Hildreth Quarry)	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Fitchburg ⓘ Rollstone Hill Quarries	[Opal-A var: Opal-AN] P Cristofono collection
ⓘ South Street construction site	[Opal-A var: Opal-AN] P Cristofono collection , 2009
Hardwick ⓘ Quabbin Aqueduct shaft No. 10 locality	[Opal-A var: Opal-AN] Gleba, 1978. Massachusetts Mineral & Fossil Localities
Leominster ⓘ Jungle Road area	[Opal-A var: Opal-AN] P. Cristofono collection
ⓘ Lunenburg	[Opal-A var: Opal-AN] T Mortimer collection
ⓘ Route 13 area	[Opal-A var: Opal-AN] P Cristofono collection
Minnesota ⓘ Washington County	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
ⓘ Mississippi	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Claiborne Co.	[Opal] Journal of the Mississippi Academy of Sciences, Jan. 2004
Tallahatchie Co. ⓘ Charleston	[Amber] Robert C. Beste, PG (2005) A Location Guide for Rock Hounds in the United States. 3rd ed. Hobbit Press, St. Louis. 149p.
Tippah County ⓘ Fuller's Earth; Ripley; Mississippi	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Fullers Earth; Blue Mountain; Mississippi	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Tishomingo County ⓘ Eastport	[Opal] Lowe, EN (1919) Mississippi its geology, geography, soils and resources. Mississippi State Geological Survey, Bulletin 14
ⓘ Paden	[Amber] Lowe, EN (1919) Mississippi its geology, geography, soils and resources. Mississippi State Geological Survey, Bulletin 14
Missouri Camden County ⓘ Decaturville crater	[Opal] Sherwood, M. D., & Williams, G. A. (1998). Missouri mineral locality index. Rocks & Minerals, 73(2), 98-117.
ⓘ Chariton County	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
Jackson County ⓘ Westerville Limestone	[Opal] Rocks & Min., March 1998.
Newton County Seneca ⓘ American Tripoli	[Opal] USGS Bulletin 340J
ⓘ Stella	[Opal] Dake, Fleener & Wilson, 1938. Quartz Family Minerals
Wayne County ⓘ Granite Knob (Granite Bend)	[Opal-A var: Opal-AN] Sherwood, M. D., & Williams, G. A. (1998). Missouri mineral locality index. Rocks & Minerals, 73(2), 98-117.
Montana ⓘ Beaverhead Co.	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
Big Horn Co. ⓘ Pryor Mountains	[Opal] Anita Moore-Nall and David R. Lageson (2015) Elevated REE in Ore Minerals of the Pryor Mountain Mining District, South Central Montana. 2015 Mining and Mineral Symposium, Montana Bureau of Mines and Geology pp47-49.
Fergus Co. South Moccasin Mountains ⓘ Whiteware Clay occurrence (Lewistown Kaolinite)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Gallatin Co.	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
ⓘ Three Forks Placer	[Opal] Rob Lavinsky specimen
Jefferson Co. Clancy-Lump Gulch Mining District ⓘ W. Wilson Mine (Liverpool Mine)	[Opal-A var: Opal-AN] Meschter, D. Y. (1953). The Geology and Mineralogy of the W. Wilson Mine Near Clancey, Jefferson County, Montana. US Department of the Interior, Geological Survey. Trace Elements Investigations Report 256
Elkhorn Mining District ⓘ Golden Curry Mine (Sourdough mine; Jacqueline; Jacquemin)	[Opal] Knopf, A. (1913) Ore Deposits of the Helen Mining Region, Montana. United States Geological Survey, Bulletin 527, 143 pages.
Lewis and Clark Co. Blue Cloud Mining District ⓘ Dutro Mine (Old Dominion)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Madison Co. Lower Hot Springs Mining District (Norris Mining District) ⓘ Red Bluff	[Opal] USGS Bull 574
Missoula Co. ⓘ Pattee Canyon	[Opal] University of Adelaide - Tate Museum collection # 22842. Ex. O.W Florke Collection
Ravalli Co. ⓘ Cathedral Rock pluton	[Opal] WC van Laer, 2009
Wibaux Co. ⓘ St Philips	[Opal] Gobla, M.J. (2012) Montana mineral locality index. Rocks & Minerals, 87, #3, 208-240; Chris Tucker and John Betts specimens.
Nebraska ⓘ Boyd Co.	[Opal]
ⓘ Brown Co.	[Opal]
ⓘ Ainsworth	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Chase Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Cherry Co.	[Opal]
ⓘ Valentine	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Cheyenne Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
Cuming Co. ⓘ West Point	[Opal] Rocks & Minerals (1955) 30:372
Custer Co. ⓘ Arnold	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Dawes Co.	[Opal] R.J. Dunham (1955) Uranium Minerals in Oligocene Gyupsum Near Chadron, Dawes County, Nebraska. USGS Rept. TEI-525
ⓘ Deuel Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Chappell	[Opal] Zeitner (1956), Midwest Gem Trails
Dodge Co. ⓘ Fremont	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Douglas Co.	[Opal] Jay Ellis Ransom,1974,Gems and Minerals of America
ⓘ Furnas Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Beaver City	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Harlan Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Republican City	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Keya Paha Co.	[Opal]
ⓘ Kimball Co.	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
Morrill Co. ⓘ Angora	[Opal] The Minerals and Gemstones of Nebraska CSD U Neb EC 2
ⓘ Bridgeport	[Opal] MacFall (1975) Gem Hunter's Guide
ⓘ Scotts Bluff Co.	[Opal] Jay Ellis Ransom,1974,Gems and Minerals of America
ⓘ Sheridan Co.	[Opal] Jay Ellis Ransom,1974,Gems and Minerals of America
ⓘ Sioux Co.	[Opal] Jay Ellis Ransom,1974,Gems and Minerals of America
ⓘ Nevada	[Opal] Gübelin, E. and Wolgensinger, M. (1976) Edelstenen. Uitgeverij Artis, Brussel (in Dutch).
Carson City Delaware Mining District ⓘ Brunswick Canyon	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Churchill County Dixie Valley Mining District ⓘ Dixie Comstock mine	[Opal] Econ Geol (1994) 89:707-719
ⓘ Dixie Valley	[Opal] LUTZ, Susan Juch EPISODIC HOT SPRING ACTIVITY AND PALEOSEISMOLOGY OF THE DIXIE VALLEY FAULT IN NORTHERN DIXIE VALLEY, NEVADA GSA Rocky Mountain - 54th Annual Meeting (May 7–9, 2002)
ⓘ Cottonwood Canyon	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Leete Mining District ⓘ Bradys Hot Springs	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Salt Wells basin	[Opal] Cahit Helvaci, Federico Ortí, Javier García-Veigas, Laura Rosell, Ibrahim Gündoğan (2012). Neogene Borate Deposits: Mineralogy, Petrology and Sedimentology; A workshop with special emphasis on the Anatolian deposits International Earth Science Colloquium on the Aegean Region (IESCA-2012, İzmir, Turkey). 64pp.
Wild Horse Mining District Shoshone Creek Canyon ⓘ Red Bird Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Clark County Gold Butte Mining District ⓘ Horse Springs claims	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Muddy Mountains ⓘ Bitter Springs trail	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Muddy Mountains Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Virgin Mountains ⓘ Bunkerville Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Douglas County Pine Nut Mountains Delaware Mining District ⓘ Julietta prospect	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Elko County Coal Mine Mining District ⓘ Coal Canyon Mine (Garnet claims)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Contact Mining District ⓘ Silver Star Mine (Alabama Mine [?]; Silver Queen Mine [?])	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Delano Mining District ⓘ Indian Springs Tungsten Mine (Gamble Ranch Mine; Ludwig Tungsten Mine; Tunnel Mine)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Podner claims	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Tin occurrence	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Dolly Varden Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Ferber Mining District ⓘ Unnamed prospect	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Gold Circle Mining District (Midas Mining District) ⓘ Red Arrow claims	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Huntington Creek Mining District ⓘ Opal; Opal Annex claims (White Hill No. 1)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Ivanhoe Mining District	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada; American Mineralogist (1988): 73: 145-152.; USGS Open-File Report 76-56
ⓘ Coleman group (Midas)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Fox Mine (Pangburn property; Governor group)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Governor Mine (Hunt property; Silver Fox Mine; Combination Mine; Florence Mine; Portland claims)	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Hatter prospect	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Hollister deposit (Ivanhoe/USX; Butte; Velvet; Clementine)	[Opal] Cain, P., & Eng, P. (2007). Technical Report on the Feasibility Study for the Hollister Development Block Gold Project, Elko County, Nevada. Project No: 2007CM16 National Instrument 43-101
ⓘ Jackson & Surprise claims	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Lark group (Rattlesnake; Lucky Boy; Davis and Roseberry; Cinnabar group; Ivanhoe; Lark Quick)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Old Timer Mine	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Redboy group	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Rimrock and Homestake Mines (Wilburg Mine; Ivanhoe Cinnabar Mine)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Silver Cloud Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Silver Cloud Mine (New Verde Mine)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada; Am Min 64:3-4 pp 1026-1038; NBMG Open File report 83-9
ⓘ Unnamed Mercury prospects (IV-18)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Velvet Mine	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Jarbidge Mining District	[Opal-A var: Opal-AN] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Kinsley Mining District ⓘ Kinsley Mountain deposit	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Loray Mining District ⓘ Unnamed workings (Alabama; New Deal; May Bell; Lost Hope; Silver Bell; Silver Star claims?)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Mountain City Mining District	[Opal] USGS Open-File Report 76-56
Mud Springs Mining District ⓘ Bellehelen mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Pequop Mining District ⓘ Oasis	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Railroad Mining District	[Opal] USGS Bull 1162B
Rock Creek Mining District ⓘ Horse Mountain mine (Staggs and Quilici group)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Silver V claims (Fisher prospects)	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
ⓘ Teapot Mine	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Ruby Valley Mining District ⓘ Sulphur Hot Spring	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Scraper Springs Mining District ⓘ Willow claims	[Opal] NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
Esmeralda County Coaldale Mining District ⓘ Blanco mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Cuprite Mining District ⓘ Ralston prospect (Eclipse)	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Sulfur Prospect No. 1	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Fish Lake Valley Mining District ⓘ B&B mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada; Am Min 64:3-4 pp 1026-1038; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Buckskin mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ Crimson Crown mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ F & L mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Last One Prospect	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ McNutt mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ Red Rose mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ Sundown mine	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
Gilbert Mining District ⓘ NBMG Sample Site 1268	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Goldfield Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Montezuma Mining District ⓘ Montezuma prospect	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
Red Mountain Mining District ⓘ Black Rock prospect	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ Rhyolite Ridge Li-B Deposit	[Opal-A var: Opal-AN] American Mineralogist 19:268-274
Silver Peak Range ⓘ Esmeralda formation	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Tokop Mining District ⓘ Empress Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Tonopah Mining District ⓘ Garibaldi claim group	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
ⓘ Silver Queen claim group	[Opal] NBMG Bull 78 Geology and Mineral Deposits of Esmeralda County, Nevada
Eureka County Beowawe Mining District ⓘ Beowawe Hot Springs	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada; USGS Bull 1998
Carlin Trend Maggie Creek Mining Subdistrict ⓘ Gold Quarry Mine	[Opal] Foord, E.E., Jensen, M., Rota, J.C. (1995) The Gold Quarry Mine, Carlin-Trend, Eureka County, Nevada. The Mineralogical Record: 26(5): 449-469.
Grass Valley ⓘ Walti Hot Springs	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Lynn Mining District ⓘ Goldstrike Mines	[Opal-A var: Opal-AN] NBMG Spec. Pub. 31 Minerals of Nevada
Humboldt County ⓘ Allied Group Nos. 1-22	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Awakening Mining District ⓘ Sleeper mine	[Opal] Econ Geol (1994) 89:628-638; USGS Bull 2090; Jackson, R. G., & Chevillon, C. V. (2007) 3D Geochemical and Mineralogical Model of the Sleeper Low Sulphidation Gold System, Nevada. Poster presentation - Exploration 07. Toronto; WARREN, I. (2005) Geology, geochemistry, and genesis of the El Pe˜nón epithermal Au-Ag deposit, northern Chile: Characteristics of a bonanza-grade deposit and techniques for exploration. Unpublished Ph.D. thesis, New Zealand, University of Auckland, Auckland, New Zealand, 428 pp. U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Donnelly Mining District ⓘ Hoss opal mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Little Joe opal mine (Black Rock mine; Little Jo mine)	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Royal Rainbow Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
McDermitt Caldera Center ⓘ Thacker Pass deposit	[Opal] Castor, S.B.; Henry, C.D. (2020) Lithium-Rich Claystone in the McDermitt Caldera, Nevada, USA: Geologic, Mineralogical, and Geochemical Characteristics and Possible Origin. Minerals 10, 68.
Montana Mountains Disaster Mining District ⓘ Disaster Peak property (Nevada Cinnabar Group; Bretchell Mercury Deposit)	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Old Man Spring Prospect	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
National Mining District ⓘ Buckskin Mountain	[Opal] Econ Geol (1985) 80:360-393
ⓘ Buckskin National mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Opalite Mining District ⓘ Cordero Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ McDermitt Mine	[Opal] NBMG Bull 59 Geology and Mineral Resources of Humboldt County, Nevada
Osgood Mountains Potosi Mining District ⓘ Redhouse Barite Mine	[Opal] Williams, S.A. (1979) Curetonite a new phosphate from Nevada. The Mineralogical Record: 10: 219-221.
Rabbit Hole Mining District ⓘ Humboldt Sulphur Company Mine	[Opal] Adams, George I. The Rabbit Hole Sulphur Mines Near Humboldt House, Nev. In: Contributions to Economic Geology 1903 United States Geological Survey Bulletin 225 Government Printing Office, Washington DC 1904
ⓘ Rabbit Hole Sulfur Mine	[Opal] Adams, George I. The Rabbit Hole Sulphur Mines Near Humboldt House, Nev. In: Contributions to Economic Geology 1903 United States Geological Survey Bulletin 225 Government Printing Office, Washington DC 1904
Santa Rosa Range ⓘ Firestone Opal Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Sulphur Mining District ⓘ Peterson Pit	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Sulphur ⓘ Hycroft Mine	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Lewis pit	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Virgin Valley	[Opal] NBMG files No. 50600003; Nevada Bureau of Mines and Geology NBMG Open-File Report 96-3 By Stephen B. Castor, Christopher D. Henry, Lisa A. Shevenell; Christopher Wentzell & Alvin Wentzell collections
ⓘ April Fool group	[Opal] USGS Bull 1538D
ⓘ Becky-Mucket claims	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada; USGS Bull 1538D
ⓘ Black Hope group	[Opal] Christopher Wentzell; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Black Peacock Mine (Birdlebough Mine; Royal Peacock Black No. 1 & No. 2 lodes)	[Opal] Eckert, Allen W. (1997) The World of Opals. (John Wiley & Sons, New York). p. 312,310.
ⓘ Bonanza Opal Mine (Virgin Mine; Virgin Opal Mine; Bon 1-5 lodes; Defiance Mine; Mathewson-Dow Opal Mine)	[Opal] USGS Bull 1538D U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Cloud Nine Opal Mine (WRT Cloud Nine claim; BLM-NMC#865658)	[Opal] Christopher Wentzell collection.
ⓘ Eddy group	[Opal] USGS Bull 1538D
ⓘ Green Fire Mine	[Opal] Christopher Wentzell
ⓘ Jo Lu 55 Opal Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Lemon Meringue Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada; Extra Lapis - English No. 10 Opal
ⓘ Opal Queen group	[Opal] USGS Bull 1538D U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Rainbow Ridge Mine (Monarch Opal Mine; Roop Mine)	[Opal] USGS Bull 1538D U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Rincon Belle Extension	[Opal] Keith Hodson, (1994) personal communication to Christopher Wentzell.
ⓘ Royal Peacock Group Mines	[Opal] USGS Bull 1538D U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Swordfish Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Toni Fire Opal Mine (Kaleidoscope Fire Opal)	[Opal] Christopher Wentzell;
ⓘ Unnamed Opal prospect	[Opal] NBMG Spec Pub 31 Minerals of Nevada
WRT Stonetree group ("Dominion Opal Mine") ⓘ Black Beauty Opal Mine (WRT Black Beauty claim; BLM-NMC No. 865656)	[Opal] Christopher Wentzell collection.
ⓘ Stonetree Opal Mine (WRT Stonetree claim; BLM-NMC No. 865655)	[Opal] Sinkankas, John (1959) Gemstones of North America. Figure 30 at page 116.
ⓘ WRT Fiddles & Diddles Opal claim	[Opal] Christopher Wentzell, dug 2013 October; known since 1994,C. Wentzell collection
ⓘ WRT Fiery Embers claim	[Opal] Christopher N. Wentzell
ⓘ WRT Sacred Fire claim	[Opal] various contributors (2013) Nevada-Jackpot! Mineral Monograph 18, Lithographie LLC, 59
Virgin Valley Mining District ⓘ Kelley Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Meyer Group Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Lander County Battle Mountain Mining District ⓘ Elephant Head area	[Opal] USGS Bull 2009
Birch Creek Mining District ⓘ Lowboy mine	[Opal] Garside NBMG Bull 81 (1973); Nevada Bureau of Mines and Geology Online Documents OF06-19 - Nevada Uranium and Thorium Occurrences
ⓘ Daisy Creek (Dacie Creek)	[Opal] Page, L. R.; Stocking, H. E.; Smith, H. B. (1956) Contributions to the geology of uranium and thorium by the United States Geological Survey and Atomic Energy Commission for the United Nations International Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955. USGS Professional Paper 300 pp303-319.
ⓘ Izenhood Mining District	[Opal] Fries, Carl, Jr., Tin deposits of northern Lander County, Nevada. USGS Bulletin 931-L, p. 279-294, illus., 1942.
ⓘ Mayflower claim (East Shaft)	[Opal] NBMG Bull 80 Geology and Mineral Deposits of Lander County, Nevada
ⓘ Modoc No. 6 claim (West Shaft)	[Opal] NBMG Bull 80 Geology and Mineral Deposits of Lander County, Nevada U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ McCoy Mining District	[Opal] NBMG Bull 80 Geology and Mineral Deposits of Lander County, Nevada
ⓘ McCoy-Strong	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Peacock-Eckman	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Reese River Mining District ⓘ Apex Mine (Rundberg Mine; Early Day Mine)	[Opal] Jensen, M. and J. Herrmann (2012) Uranium mineralization at the Apex Mine, Lander County, Nevada. Rocks and Minerals 87:270-276
ⓘ Rock Creek Property	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Spencer Hot Springs Mining District ⓘ Linka Mine	[Opal-A var: Opal-AN] Rolf Luetcke
Lincoln County Chief Mining District ⓘ Lucky Chief mine	[Opal] NBMG Bull 73 Geology and Mineral Resources of Lincoln County, Nevada U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Mormon Mountains Mormon Mountains District ⓘ Webber Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Panaca Mining District	[Opal] Page, L. R.; Stocking, H. E.; Smith, H. B. (1956) Contributions to the geology of uranium and thorium by the United States Geological Survey and Atomic Energy Commission for the United Nations International Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955. USGS Professional Paper 300 pp303-319.
ⓘ Morgan and Bush mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia
Lyon County ⓘ Fernley	[Opal] USGS Minerals Yearbook - Diatomite 1998
ⓘ Southwest	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Ramsey Mining District ⓘ DeLongchamps prospect	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Singatse Range Yerington Mining District ⓘ Carson Hill	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Ludwig ⓘ Ludwig Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Talapoosa Mining District ⓘ Talapoosa mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Mineral County ⓘ Fishlake Valley	[Opal] Van King
Fitting Mining District ⓘ Gillis prospect (Gillis Iron Nos. 1 & 2 claims)	[Opal] NBMG Bull 58 Geology and Mineral Resources of Mineral County, Nevada U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Rawhide Mining District ⓘ Stockton Property	[Opal] NBMG Bull 58 Geology and Mineral Resources of Mineral County, Nevada
Red Ridge Mining District ⓘ Bubbles group	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Robinson group	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Toquima Range Barcelona Mining District (Spanish Belt Mining District) ⓘ Lucky Ann	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Nye County Bare Mountain ⓘ Bare Mountain Mining District (Fluorine Mining District)	[Opal] Rob Lavinsky specimen
Beatty ⓘ Harvey Mine (Telluride Mine)	[Opal] NBMG Bull 77 Geology and Mineral Resources of Southern Nye County, Nevada
ⓘ Meiklejohn Mountain	[Opal] Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 558.
ⓘ BVC Claims	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Cinnabar prospect	[Opal] USGS Bull 620D
ⓘ Hogback Ridge	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Mammoth group Nos. 1-3	[Opal] USGS Bull 620D
ⓘ Mammoth No. 5 prospect	[Opal] USGS Bull 620D
ⓘ Thompson Mine	[Opal] NBMG Bull 77 Geology and Mineral Resources of Southern Nye County, Nevada
ⓘ Tip Top Mine	[Opal] NBMG Bull 77 Geology and Mineral Resources of Southern Nye County, Nevada
Gabbs Mining District ⓘ Opaline silica quarry of Basic Inc.	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Jackson Mining District ⓘ Warcloud Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Paradise Peak Mining District ⓘ Ketchup Flat deposit	[Opal] Econ Geol (1994) 89:1228-1248
San Antonio Mountains ⓘ Tonopah Mining District	[Opal] Page, L. R.; Stocking, H. E.; Smith, H. B. (1956) Contributions to the geology of uranium and thorium by the United States Geological Survey and Atomic Energy Commission for the United Nations International Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955. USGS Professional Paper 300 pp351-359
Tonopah ⓘ Mizpah Mine (Mizpah shaft)	[Opal-A var: Opal-AN] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Valley View vein	[Opal-A var: Opal-AN] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Starfire mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Toquima Range Manhattan Mining District Manhattan ⓘ Manhattan Consolidated Mine	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Train prospect (Tom Molly Mine)	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Northumberland Mining District ⓘ Northumberland Mine	[Opal] MinRec 16(1):37-41.
ⓘ Yucca Mountain	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada; Nevada Bureau of Mines and Geology NBMG Open-File Report 96-3 By Stephen B. Castor, Christopher D. Henry, Lisa A. Shevenell
Pershing County Antelope Mining District Lovelock ⓘ Unnamed Zeolite deposit [1]	[Opal] USGS Minerals Yearbook - Diatomite 1998
Antelope Springs Mining District ⓘ Red Bird Mine	[Opal-A var: Opal-AN] NBMG Spec. Pub. 31 Minerals of Nevada
Buena Vista Valley ⓘ Kyle Hot Springs	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Goldbanks Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Goldbanks mine	[Opal] U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Imlay Mining District ⓘ Florida Canyon mine	[Opal] U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Jersey Mining District (Jersey Valley Mining District)	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Nightingale Mining District ⓘ Sage Hen Springs Prospect	[Opal-A var: Opal-AN] Larry J, Garside (1973). Radioactive mineral occurrences in Nevada. p. 94
Seven Troughs Mining District ⓘ Unnamed Locality	[Opal] Robert E. Walstrom Collection
Table Mountain Mining District ⓘ Black Dyke Claim	[Opal] U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Shoshone Mountains ⓘ Mule Canyon deposit	[Opal] David A. John, Albert H. Hofstra, Robert J. Fleck, Jon E. Brummer, and Eric C. Saderholm (2003)Geologic setting and genesis of the Mule Canyon low-sulfidation epithermal gold-silver deposit, north-central Nevada (in Gold deposits in northern Nevada; Part 1, Regional studies and epithermal deposits). Economic Geology and the Bulletin of the Society of Economic Geologists 98(2):425-463
Storey County Castle Peak Mining District ⓘ Washington Hill mine	[Opal] NBMG Bull 70 Geology and Mineral Resources of Washoe and Storey Counties, Nevada
ⓘ Comstock Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Washoe County ⓘ Lost Creek	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Mahogany Peak	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Orion Group (Gillam; Boar; Ymer)	[Opal] U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Pyramid Lake ⓘ Needle Rocks	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
Pyramid Mining District ⓘ Lowary mine (Maue-Mcray mine)	[Opal] NBMG Bull 70 Geology and Mineral Resources of Washoe and Storey Counties, Nevada
ⓘ Red Bluff mine	[Opal] NBMG Bull 70 Geology and Mineral Resources of Washoe and Storey Counties, Nevada; NBMG Spec. Pub. 31 Minerals of Nevada; Nevada Bureau of Mines and Geology NBMG Open-File Report 96-3 By Stephen B. Castor, Christopher D. Henry, Lisa A. Shevenell; Lapointe, D. D., Price, J. G., Faulds, J. E., DePolo, C. M., & Davis, D. A. (2012). " Tuff All Over", Exploring Faulted Volcanic Terrain in the Painted Hills, Virginia Mountains, West of Pyramid Lake. Nevada Bureau of Mines and Geology.
San Emidio Mining District ⓘ San Emidio prospect (Mud Flat prospect)	[Opal] NBMG Bull 70 Geology and Mineral Resources of Washoe and Storey Counties, Nevada; U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Wind Mountain mine	[Opal] U.S. Geological Survey, (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Steamboat Springs Mining District	[Opal] MinRec 16(1):25-31
ⓘ Faith clay pit	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
ⓘ Steamboat Hot Springs	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Steamboat Springs mine	[Opal] NBMG Bull 70 Geology and Mineral Resources of Washoe and Storey Counties, Nevada
ⓘ Wall Canyon	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
White Pine County ⓘ Currant Mining District	[Opal] NBMG Spec. Pub. 31 Minerals of Nevada
New Hampshire Carroll County Albany ⓘ Government pit (Government gravel pits)	[Opal-A var: Opal-AN] Rocks & Min. 80:243
Conway ⓘ Lovejoy Gravel pits (Lovejoy pit)	[Opal-A var: Opal-AN] No reference listed
Hale's Location ⓘ Middle Moat Mountain locality (Moat Mountain)	[Opal-A var: Opal-AN] P Cristofono collection, 2010
ⓘ Ossipee	[Opal-A var: Opal-AN] Smith, Art. "New Hampshire: mineral locality index " in Rocks & Min., July-Aug 2005
ⓘ Gulch locality (Raccoon Gulch; Folsom Brook Gulch)	[Opal-A var: Opal-AN]
Wakefield ⓘ Ham and Weeks Mine (Weeks Feldspar Quarry; Ham-Weeks pegmatite)	[Opal] P. Cristofono collection (ex. Gene Bearss)
Cheshire County Marlow ⓘ Turner Mine	[Opal-A var: Opal-AN] P. Cristofono collection, 2012
Surry ⓘ Mine Ledge	[Opal] Van King
ⓘ Walpole	[Opal] Van King
ⓘ Chickering Mine	[Opal-A var: Opal-AN] P. Cristofono, T. Mortimer, J.W. Nizamoff, A. Wilken, and R. Wilken (2011) The 38th Rochester Mineralogical Symposium, April 14-17, 2011, lecture abstracts, page 17-18.
Grafton County Bethlehem ⓘ North Sugarloaf Mountain locality	[Opal] Rocks & Minerals Vol.65 No.4; Rocks & Minerals (2005) 80:242-261 New Hampshire Mineral Locality Index
Groton ⓘ Palermo No. 1 Mine	[Opal-A var: Opal-AN] Whitmore & Lawrence, 2004. The Pegmatite Mines Known As Palermo, p.187
Orange ⓘ Keyes Mica Quarries	[Opal] Thompson, W. B., Falster, A. U., & Mortimer, T. J. (2022). The Keyes Mica Mines, Orange, Grafton County, New Hampshire. Rocks & Minerals, 97(4), 302-329.
Hillsborough County ⓘ Bedford	[Opal-A var: Opal-AN] P. Cristofono collection 2011
ⓘ Pulpit Road locality	[Opal-A var: Opal-AN] P. Cristofono collection
ⓘ Merrimack	[Opal-A var: Opal-AN] P Cristofono collection; P Cristofono collection
ⓘ Route 101A construction site	[Opal-A var: Opal-AN] P Cristofono collection
Wilton ⓘ Wilton Crushed Stone Quarry (Pike Industries Quarry; Quinn Brothers Quarry; LAW Inc. Quarry)	[Opal-A var: Opal-AN] P. Cristofono collection
Merrimack County Hooksett ⓘ Hooksett Crushed Stone Quarry (Pike Industries Quarry)	[Opal-A var: Opal-AN] P. Cristofono collection 2011
Rockingham County Fremont ⓘ Route 107 area	[Opal-A var: Opal-AN] P Cristofono collection , 2009
ⓘ Raymond	[Opal-A var: Opal-AN] P. Cristofono collection, 2012
Salem ⓘ Foster Corners	[Opal-A var: Opal-AN] P. Cristofono collection 2011
Windham ⓘ Ledge Rd. locality	[Opal-A var: Opal-AN] P. Cristofono collection, 2010
Strafford County Strafford Parker Mountain ⓘ Parker Mountain Mine (Buzzo Mine; Foss Mine; Foss Ledge Mine)	[Opal-A var: Opal-AN] Rocks & Min.:64:504.; Rocks & Minerals 80:4 pp234-241
Sullivan County South Acworth ⓘ Beryl Mountain Quarry	[Opal-A var: Opal-AN] Jeremy Zolan Collection
Springfield ⓘ Colby Mine (Joe Hill Mine)	[Opal] P. Cristofono collection, 2015
ⓘ New Jersey	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Burlington Co. Southampton Township ⓘ Vincentown	[Amber] Kunz,1892. Gems & Precious Stones of N. America, p.200.
Camden Co. ⓘ Camden	[Amber] D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
Essex Co. Montclair Upper Montclair ⓘ McDowell's Quarry (Osborne and Marsellis Quarry)	[Opal] Mins. of NYC & Its Environs, NY Min. Club (1931), Manchester, J.G.; Rocks & Min.: 59-157-183 (1984), Peters, Joseph J.
Verona ⓘ F.J. Marley Quarry	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull., Vol. 3, No. 1, Manchester, J.G. (1931): 96.
Gloucester Co. South Harrison Township Harrisonville ⓘ Old Man's Creek	[Amber] Kunz,1892. Gems & Precious Stones of N. America, p.201.
Hudson Co. Bergen Hill Weehawken ⓘ New York - West Shore & Buffalo RR tunnel	[Opal-A var: Opal-AN] The Minerals of New York City and Its Environs, NY Mineralogical Club (1931), Manchester, J.G.; Canfield (1889).
Jersey City Bergen Hill Mt Pleasant ⓘ Pennsylvania Railroad cut	[Opal-A var: Opal-AN] Mins. of NYC & Its Environs, NY Min. Club., Vol. 3 (1931), edited by J.G. Manchester
Mercer Co. Hamilton Township ⓘ Crosswicks Creek	[Amber] A Quest for New Jersey Minerals, Robert Speiser(1978).; D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
West Windsor Township ⓘ Margerum Brothers Quarry	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 88.
Middlesex Co. ⓘ Dunellen	[Opal] The Minerals of NYC & Its Environs, NY Min. Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 71.
New Brunswick ⓘ Burnt Woods	[Amber] The Minerals of NYC & Its Environs, NY Min. Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 68.
ⓘ Sayreville	[Amber] A Quest for New Jersey Minerals, Robert Speiser(1978).
ⓘ South Amboy Borough	[Amber] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 5, No. 1, Manchester, J.G. (1931): 92.
ⓘ South River Borough	[Amber] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 5, No. 1, Manchester, J.G. (1931): 92.
Monmouth Co. Belmar (Belmar Borough) ⓘ Shark River	[Amber] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 5, No. 1, Manchester, J.G. (1931): 91; A Quest for New Jersey Minerals, Robert Speiser(1978).
Morris Co. Mine Hill Township ⓘ Dickerson Mine	[Opal] Canfield FA (1898) Catalogue of Minerals found in New Jersey. in Final Report of the State Geologists.; The Iron Mines of New Jersey (1910), Bayley:358-362
Mount Olive ⓘ Lowrance Mine	[Opal-A var: Opal-AN] NJ State Geol. Ann. Rpt. (1856):175.
Rockaway Township ⓘ Allen Mine	[Opal] The Iron Mines of NJ (1910), Bayley:404; NJ State Geol. Ann. Rpt (1856):197.
Passaic Co. Little Falls Township Great Notch ⓘ Francisco Brothers Quarry (Francisco Quarry)	[Opal] Mins. of NYC & Environs, NY Min. Club (1931), Manchester.
Paterson ⓘ Upper New Street Quarry	[Opal-A var: Opal-AN] American Muiseum of Nat. History, NY, specimen(s); Paterson, NJ, Museum specimens; Rocks & Min.: 59:157-183, Peters, Joseph J. (1984).
Salem Co. Pennsville Township ⓘ Harrisonville (Pigseye; Pigs Eye)	[Amber] D. M. Schlegal (1959) Gem Stones of the United States. USGS Bulletin 1042G
Somerset Co. Bernards Township ⓘ Millington Quarry	[Opal] Kent, B.P. and Butkowski, B. (2000): Minerals of the Millington Quarry, Somerset County, New Jersey. Mineralogical Record, 31: 411.
Warren Township ⓘ Stirling Brook ("Carnelian Creek")	[Opal] Speiser, Robert (1978) A Quest for New Jersey Minerals: 10.(privately published).
Sussex County Byram Township Cranberry Lake ⓘ BEMCO prospect (Charlotte Mine)	[Opal-A var: Opal-AN] collected by David Bernstein- 10/2009
Franklin Mining District Franklin Franklin Mine ⓘ Buckwheat dump mineral collecting site	[Opal] King, Vandall T, et. al. 2022, Mineralogy of Franklin and Ogdensburg, New Jersey
Ogdensburg ⓘ Sterling Hill	[Opal] Kuitems, Steven, Orosz, Joe, and Nikischer, Tony (2009) Mineral #357 Found at Franklin, NJ, Picking Table v50 (1), p 17.
Union Co. ⓘ Summit	[Opal] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931):94.
Warren Co. Franklin Township ⓘ New Village	[Opal] Yale Peabody Museum 3979
ⓘ Hackettstown	[Opal] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull., Vol. 3, No. 1, Manchester, J.G. (1931): 76.
New Mexico Bernalillo County ⓘ Isleta Pueblo	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Carlsbad Potash District	[Opal] Northrop, Minerals of New Mexico, 3rd. rev. ed. (1996)
Catron County ⓘ Taylor Creek Mining District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Juniper locality	[Opal] NMGS 37th Field Conference
ⓘ Nugget Gulch	[Opal] NMGS 37th Field Conference
Sawmill Creek ⓘ Unnamed prospects	[Opal] NMGS 37th Field Conference
Cibola County Laguna subdistrict ⓘ Woodrow Mine (Woodrow breccia pipe)	[Opal] NMBMMR Memoir 15 Geology and Technology of the Grants Uranium Region; Moench, Robert Hadley; Schlee, John Stevens (1967) Geology and uranium deposits of the Laguna district, New Mexico. USGS Prof. Paper 519
Colfax County Springer Point of Rocks Mesa (Pecks Mesa) ⓘ Point of Rocks Quarry	[Opal-A var: Opal-AN] Northrop, Minerals of New Mexico, 3rd. rev. ed. (1996)
Doña Ana County Rincon Mining District ⓘ Palm Park	[Opal] Minerals of New Mexico 3rd ed.
Grant County ⓘ Alum Mountain Mining District (Alum Mining District)	[Opal] Northrop, Minerals of New Mexico, 3rd. rev. ed. (1996)
ⓘ Burro Mountains Mining District	[Opal] Minerals of New Mexico 3rd ed.
Tyrone Area ⓘ Porterfield Mine	[Opal] NMBMMR Bull 83 Mineral Deposits of Western Grant County, New Mexico
Cap Rock Mountain Mining District ⓘ Cliff Roy Mine	[Opal] NMBMMR Bull 83 Mineral Deposits of Western Grant County, New Mexico U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Central Mining District (Bayard District)	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Fort Bayard	[Opal] Minerals of New Mexico 3rd ed. U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Sweeny Mine	[Opal] Robert E. Walstrom Collection
ⓘ Faywood Hot Springs	[Opal] Minerals of New Mexico 3rd ed.
Gila National Forest ⓘ Black Canyon	[Opal] Minerals of New Mexico 3rd ed.
Pinos Altos Mining District ⓘ Cross Mountain Road	[Opal-A var: Opal-AN] Identified on specimens obtained at 2009 Tucson micromount symposium
ⓘ Santa Rita Mining District	[Opal] Minerals of New Mexico 3rd ed.
White Signal Mining District ⓘ Merry Widow Mine	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
ⓘ Tullock Shaft	[Opal] NMBMMR Bull 83 Mineral Deposits of Western Grant County, New Mexico
Hidalgo County ⓘ Antelope Wells prospect	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.; Page, L. R.; Stocking, H. E.; Smith, H. B. (1956) Contributions to the geology of uranium and thorium by the United States Geological Survey and Atomic Energy Commission for the United Nations International Conference on Peaceful Uses of Atomic Energy, Geneva, Switzerland, 1955. USGS Professional Paper 300 pp97-103
ⓘ Hatchet Mountains	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Peloncillo Hills	[Opal] Minerals of New Mexico 3rd ed.
Peloncillo Mountains San Simon Mining District ⓘ Copper Queen claim	[Opal] USGS Prof Paper 68 The Ore Deposits of New Mexico
Granite Gap ⓘ Bob Montgomery Claim Group	[Opal] Robert E. Walstrom Collection
ⓘ Stella Maris No. 1 Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Pyramid Mountains Lordsburg Mining District Lordsburg Virginia District ⓘ Atwood-Henry Clay Mine (Alamo Mine)	[Opal] Robert E. Walstrom Collection
ⓘ Pole Line prospect	[Opal] Robert E. Walstrom Collection
Lea County Lovington ⓘ Unspecified occurrences	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
Luna County ⓘ Deming	[Opal] Rolf Luetcke
Little Florida Mountains Little Florida Mountains Mining District ⓘ Rockhound State Park	[Opal] http://www.emnrd.state.nm.us/nmparks/PAGES/parks/rockh/rockh.htm
Tres Hermanas Mountains Tres Hermanas Mining District Mahoney Mines area ⓘ Cincinnati vein system	[Opal-A var: Opal-AN] Jerry Cone Collection
ⓘ Comfort claim	[Opal] Jerry Cone Collection; Robert E. Walstrom Collection
ⓘ Lindy Ann claims	[Opal] Jerry Cone Collection
McKinley County ⓘ Gallup Mining District	[Opal] Minerals of New Mexico 3rd ed.
Otero County Cornudas Mountains ⓘ Wind Mountain	[Opal] Laszlo Horvath collection
Rio Arriba County ⓘ Petaca Mining District	[Opal] Northrop, Minerals of New Mexico, 3rd rev. Ed., 1996
San Juan County ⓘ Chuska Mountains	[Opal] Minerals of New Mexico 3rd ed.
San Juan Basin ⓘ Fossil Forest	[Amber] Wolberg, D. L. (1994). Fossils, Rocks and Ancient Environments of the Late Cretaceous Fossil Forest Locality, San Juan Basin, New Mexico; Combining Science and Education. Maps Digest Expo XVI Edition, 126.
Sandoval County ⓘ Cochiti District	[Opal] NMBMMR Bull 81 Summary of the Mineral Resources of Bernalillo, Sandoval, and Santa Fe Counties, New Mexico
ⓘ Jemez Sulfur District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Battleship Rock	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
ⓘ Rio Puerco area	[Opal] Minerals of New Mexico 3rd ed.
Santa Fe County ⓘ Cerrillos District	[Opal] NMBMMR Bull 81 Summary of the Mineral Resources of Bernalillo, Sandoval, and Santa Fe Counties, New Mexico
ⓘ Tom Payne Mine (Tom Paine mine)	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ La Bajada Mining District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ New Placers District	[Opal] Northrop, Minerals of New Mexico, 3rd Rev. Ed., 1996
ⓘ Carnahan Mine (Lincoln-Lucky Mine)	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
ⓘ San Pedro Mine	[Opal] NMBMMR New Mexico Mineral symposium (2004)
Sierra County Caballo Mountains Mining District ⓘ Napolean - Rosa Lee prospect	[Opal] Jerry Cone Collection
Hillsboro Mining District Hillsboro Percha Creek ⓘ Big Chief Mine	[Opal-A var: Opal-AN] Rolf Luetcke
ⓘ Rex mine (Rex and Smuggler mine)	[Opal] Jerry Cone Collection
ⓘ Iron Mountain No. 2 District	[Opal] Minerals of New Mexico 3rd ed.; USGS Bull 945C
ⓘ New Mexico Highway 1 roadcut	[Opal-A var: Opal-AN] Gibbs, R. (2013) Microminerals near San Juan Peak in the San Mateo Mountains, Socorro County, New Mexico. 34th Annual New Mexico Mineral Symposium, November 9-10, Socorro, New Mexico, Program with Abstracts: 34(14): 27.
ⓘ Nugget Gulch	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
ⓘ Nunns Lease	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Paramount Canyon ⓘ Beryllium Virgin claim	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
Rio Grande Rift Zone ⓘ Jornada Del Muerto	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ San Mateo Mountains Mining District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Monticello deposit (Pitchblende Strike prospect)	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
ⓘ Terry Uranium Prospect (Terry Uranophane prospect; Hanosh property)	[Opal] NMBMMR OFR 19
ⓘ Taylor Creek Tin Mining District (Black Range Tin District)	[Opal] Northrop, Minerals of New Mexico, 3rd Rev. Ed., 1996
ⓘ The Clearing	[Opal-A var: Opal-AN] Minerals of New Mexico 3rd ed.
Socorro County ⓘ Bernardo Bridge	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Hansonburg District	[Opal] Northrop, Minerals of New Mexico, 3rd Rev. ed., 1996
ⓘ Jornada Draw	[Opal] The Mineralogist, v. 9, no. 5, p. 181.
ⓘ Ladron Mountains Mining District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Luis Lopez Manganese District	[Opal] Minerals of New Mexico 3rd ed.
ⓘ Magdalena Mining District	[Opal] Northrop, Minerals of New Mexico, 3rd. rev. ed. (1996)
ⓘ North Magdalena Mining District	[Opal] Jerry Cone Collection
Socorro Peak Mining District ⓘ Socorro Hot Springs	[Opal] Minerals of New Mexico 3rd ed.
Taos County No Agua Mining District ⓘ Brushy Mountain	[Opal] Ramon DeMark and Jessie Kline, New Mexico Mineral Symposium, November 2000
ⓘ United Perlite Mine	[Opal] NMBMMR New Mexico Mineral symposium (2000) p.11
ⓘ Union County	[Opal] Minerals of New Mexico 3rd ed.
ⓘ New York	[Amber] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 84.; Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
Broome Co. Deposit ⓘ Wheeler Quarry	[Opal-A var: Opal-AN] Rocks & Min.: 20:61.
Essex Co. Crown Point Township ⓘ Crown Point Center	[Opal-A var: Opal-AN] Jensen (1978) Minerals of New York State
ⓘ New York City	[Opal] John H. Betts (2009) "The minerals of New York City", Rocks & Minerals, 84, 204-240.
Manhattan (New York Co.) ⓘ 106th Street & Central Park West	[Opal-A var: Opal-AN] Alfredo Petrov, field observations on material displaced during hurricane Irene, August 2011.
Staten Island (Richmond Co.) ⓘ Kreischerville	[Amber] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull., Vol. 3, No. 1, Manchester, J.G. (1931): 59.; Rocks & Minerals 82:472-483
Orange Co. Town of Warwick Amity ⓘ Rhein Property	[Opal] Glenn Rhein
Edenville Edenite Hill ⓘ Pipeline Excavation	[Opal-A var: Opal-AN] Van King
Putnam Co. Town of Philipstown ⓘ Philips Mine (Philips Pyrite Mine; Anthony's Nose Pyrrhotite Mine)	[Opal-A var: Opal-AN] Rocks & Min.:8:61-65.
Town of Putnam Valley ⓘ Phillips ore bed	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 87.
Town of Southeast ⓘ Interstate 84 road cuts	[Opal-A var: Opal-AN] Januzzi, 1976. Mineral Localities of CT and Southeastern NY State, p223-224
ⓘ Tilly Foster Iron Mine	[Opal] Jensen (1978) Minerals of New York State, 42-43 (Januzzi, 1966, 1989) (Trainer, 1938).
St. Lawrence Co. De Kalb Township Bigelow ⓘ Road cut	[Opal] Rocks & Minerals 85:250-259
Westchester Co. ⓘ Bedford	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull., Vol. 3, No. 1, Manchester, J.G. (1931): 65.
ⓘ Baylis Quarry (Bayliss Quarry)	[Opal-A var: Opal-AN] Rocks & Min.:11:66; 23:712.
ⓘ Consolidated Feldspar Mining Corporation's plant	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 39 & 45-46.
Cortlandt Township Montrose ⓘ Crugers Emery Mine	[Opal] Rocks & Min.:8:39.
Toddville ⓘ Strang Emery Pit	[Opal-A var: Opal-AN] Rocks & Min.: 7:91; 8:38.
Harrison ⓘ Lake Street Quarry	[Opal-A var: Opal-AN] Rocks & Min.: 6:101 & 9:136-137.
Peekskill Camp Smith ⓘ McCoy's Gold Mine	[Opal-A var: Opal-AN] Rocks & Min.: 8:40.
ⓘ Croft Mine (Croft Magnetic Iron Mine)	[Opal-A var: Opal-AN] Rocks & Min.:7:148 & 8:40.
ⓘ White Plains	[Opal-A var: Opal-AN] The Minerals of New York City & Its Environs, New York Mineralogical Club Bull. Vol. 3, No. 1, Manchester, J.G. (1931): 98.
North Carolina ⓘ Ashe Co.	[Opal-A var: Opal-AN] Genth,Frederick Augustus (1891) The Minerals Of North Carolina;USGS Bulletion No.74
Beaufort Co. North Carolina Phosphate Mining District Aurora ⓘ Texas Gulf Sulphur Phosphate Quarry	[Amber] Sinkankas, J. (1976) Gemstones of North America, Vol. 2, p 351.
ⓘ Brunswick Co.	[Amber] World of Amber
Cabarrus Co. Charlotte Belt ⓘ Propst Mine (Nash; Heglar)	[Opal] Carpenter III, P. Albert (1976) Metallic Mineral Deposits of the Carolina Slate Belt, North Carolina : NCGS Bulletion 84
ⓘ Concord	[Opal-A var: Opal-AN] Pratt,Joseph Hyde.,(1933) Gems and Gem Minerals of North Carolina: American Mineralogist,Vol.18,No.4,April,1933
Caldwell Co. ⓘ Wilson Creek	[Opal] Luke Osborne states that he collected opal from this locality.
Clay Co. ⓘ Elf	[Opal-A var: Opal-AN] Pratt,Joseph Hyde.,1933,Gems and Gem Minerals of North Carolina: American Mineralogist: Vol.18,No.4,April,1933
Cleveland Co. Kings Mountain Mining District ⓘ Foote Lithium Co. Mine	[Opal] Collections of Kenny Gay and Steve Adams, material collected by Jason Smith
Cumberland Co. Fayetteville ⓘ Cape Fear River Formation	[Opal] Gems and Minerals of America- Jay Ellis Ransom-1974
Macon Co. Cowee Valley Ellijay Mining District Franklin Corundum Hill ⓘ Culsagee Mine	[Opal-A var: Opal-AN] Ref.: Dana 6:499, 560 & 1077.
Madison Co. Mars Hill ⓘ Carter Mine	[Opal-A var: Opal-AN] Rocks & Min.: 17:62
Mitchell Co. Cane Creek Section Bakersville Pizzle Mtn ⓘ Cloudland Mine	[Opal-A var: Opal-AN] Rocks & Min.:11:76-77.
Crabtree Creek ⓘ Bon Ami Mine	[Opal-A var: Opal-AN] Veal,William Brian (2004) Mineralogy Of The Peraluminous Spruce Pine Plutonic Suite,Mitchell,Avery, and Yancey Counties, North Carolina:B.S.,Georgia Southwestern State University
ⓘ Glenn Mine	[Opal-A var: Opal-AN] Smithsonian Institution Mineral Reference Collection No.C5279-02
Crabtree Falls Crabtree Mountain ⓘ Ballew Mine	[Opal-A var: Opal-AN] Rocks & Min.:11:58.
Grassy Creek ⓘ Grassy Creek Mine	[Opal-A var: Opal-AN] Genth,F.A and Kerr,W.C ,1881,Minerals and Mineral Localities of North Carolina,Geologic Survey, North Carolina
Hawk-Bakersville ⓘ Carter Buchanan Mica Mine	[Opal-A var: Opal-AN] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ W. C. Burleson Mica Mine (Joe Stevenson Mine)	[Opal-A var: Opal-AN] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Laster Mine	[Opal-A var: Opal-AN] Rocks & Min.: 11:58.
ⓘ Lick Ridge Mine	[Opal-A var: Opal-AN] Genth, Frederick Augustus (1891) The Minerals Of North Carolina: USGS Bulletion No.74
Little Switzerland ⓘ Hollifield Mine	[Opal-A var: Opal-AN] Rocks & Min.:11:58.
ⓘ Pittman Mine	[Opal-A var: Opal-AN] Rocks & Min.: 11:57.
Penland ⓘ Deer Park Mine	[Opal-A var: Opal-AN] Michael Streeter,2003,A Rockhounding Guide to North Carolinas Blue Ridge Mountains
ⓘ Deer Park No. 2 Mine	[Opal-A var: Opal-AN] Rocks & Min.:11:77 & 60:92.
ⓘ Pine Mountain (Pine Mountain Mine)	[Opal-A var: Opal-AN] U.S Bureau of Mines,Spatial Data Extraction from the Minerals System/Mineral Industry Location System(Mas/Mils)CD-Rom,Sep,1995
Spruce Pine ⓘ Big Crabtree road	[Opal-A var: Opal-AN] Min Rec 10:1 pp29-30
ⓘ Chalk Mountain Mine	[Opal-A var: Opal-AN] Streeter.Michael.,2003,A Rockhounding Guide to North Carolinas Blue Ridge Mountains.pg#84-85
ⓘ Lawson Mine	[Opal-A var: Opal-AN] Min Rec 10:1 pp29-30
ⓘ McKinney Mine (Power Mill Creek Mine)	[Opal-A var: Opal-AN] Ross,Clarence S.,(1937) Sphalerite from a Pegmatite near Spruce Pine,North Carolina:The American Mineralogist,May,1937
ⓘ Southers Branch Mine (Sullins Branch Mine)	[Opal-A var: Opal-AN] Rocks & Min.: 60:92.
ⓘ Sullins Branch mine	[Opal-A var: Opal-AN] Min Rec 10:1 pp29-30
ⓘ Pitt Co.	[Amber] Genth, F.A. (1891) The Minerals Of North Carolina. USGS Bulletion No. 74.; Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Stokes Co.	[Opal-A var: Opal-AN] Genth,F.A.,1891,The Minerals Of North Carolina:USGS Bulletion No.74
Swain Co. Bryson City Feldspar Mining District ⓘ Bryson Branch Gold Placers	[Opal] U.S Geological Survey ,2005,Mineral Resources Data System:U.S Geological Survey,Reston,Virginia
ⓘ Vance Co.	[Opal-A var: Opal-AN]
Hamme Tungsten Mining District Tungsten ⓘ Tungsten Queen Mine and plant (Hamme Mine; Haile Mines; Sneed-Walker)	[Opal-A var: Opal-AN] Ransom,Jay Ellis.,1974,Gems and Minerals of America
ⓘ Wayne Co.	[Amber] World of Amber
Yancey Co. Burnsville Hurricane Mountain ⓘ Ray Mica Mine (Wray Mine)	[Opal-A var: Opal-AN] C.W. Allen collection
Celo Micaville ⓘ Fanny Gouge Mine (Spruce Pine Mica Company No. 10 Mine)	[Opal-A var: Opal-AN] C.W. Allen collection
Crabtree Creek ⓘ Carolina Mineral Company No. 20 Mine (Old 20 Mine)	[Opal-A var: Opal-AN] Rocks and Minerals (1985) 60:84-93,99; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Seven Mile Ridge ⓘ Huskins Mine	[Opal-A var: Opal-AN] Rocks & Min.:11:58.
Ohio Franklin County ⓘ American Aggregates Corp. Marble Cliff Quarry (Marble Cliff Quarries Co. Scioto quarry)	[Opal] Carlson, E.H. (2015) Minerals of Ohio, 2nd ed. ODNR Division of Geological Survey, Bulletin 69, 290 pages.
Columbus ⓘ Bill Moose Run	[Opal] John Krygier specimens
Oklahoma Kiowa County Lugert ⓘ Government quarry (Lugert granite quarry)	[Opal-A var: Opal-AN] R&M 72:4 pp 252-264
ⓘ Murray County	[Opal] Rocks & Min. vol.72 (1997)
ⓘ Ottawa County	[Opal] Dake, Fleener & Wilson, 1938. Quartz Family Minerals
Oregon Baker Co. Conner Creek Mining District ⓘ Connor Creek Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Durkee	[Opal] MacFall, P.M. (1951) Gem Hunter's Guide (1st ed.). Science and Mathematics Publishing Company, 187 pages.
ⓘ Durkee Fire Opal Mine	[Opal] Tschernich, Rudy, 1992, Zeolites of the World
Swayze Creek ⓘ Durkee Opal Mine	[Opal] Micro Probe Volume VI Number 4
Clackamas Co. Clackamas River localities ⓘ Memaloose roadcut	[Opal] Bill Thompkins
Oak Grove Fork ⓘ Kiggins	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Nisbet (Oregon Quicksilver)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Columbia Co. Goble ⓘ Neer Road	[Opal] Micro Probe Vol. 6 No. 5 Fall 1987; Tschernich, R. (1992): Zeolites of the World, 117
Crook Co. Howard Mining District (Ochoco Mining District; Bolivar Mining District) ⓘ Barnes Butte (Prineville Quicksilver)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Jimmy Ann (Beardssmore; Stanley & Culbertson; Staley; Ochoco Mines Corp.; Ochoco Quicksilver Champion; Barney and Staley)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Mother Lode (American Almaden; Consolidated Quicksilver; Canyon Creek)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Post	[Opal]
Deschutes Co. Newberry National Volcanic Monument ⓘ Newberry Caldera	[Opal] Mineralogy of 10 Geothermal boreholes drilled in and around the Newberry Caldera U.S. Geological Survey Professional Paper, Issue 1578 By Keith E. Bargar, Terry E. C. Keith 1999
Harney Co. ⓘ Otis Basin Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Paiute	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Pueblo Mining District (Denio Mining District) ⓘ Blair Group (Connor - Blair)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Blue Bull Occurrence (Ionic Claims; Chukar Group)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Double Link Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Fisher (Fisher & Regal & Sheepherder Claims; Fisher and Regal Group; Doan Group)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Harmony Occurrence (Surprise Group; Ajax Claims)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Mogul	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Hood River Co. ⓘ Pucci drillhole	[Opal] Marshall W. Gannett and Keith E. Bargar; 1981 Volcanic stratigraphy and secondary mineralization of USGS Pucci geothermal test well, Mount Hood, Oregon, Open-File Report 81-1330.
Jackson Co. Ashland Mining District ⓘ Climax Gold Area Occurrence (Gypsum Occurrence)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Meridian Prospect (Phillips Property)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Butte Creek Mining District ⓘ Call of the Wild prospect (Grand Cove prospect)	[Opal] Oregon Metal Mines Handbook, 1943, Oregon Department of Geology and Mineral Industries: Bulletin No. 14-C, Vol. 2, Section 2 - Jackson Co., page 141.
Evans Creek Mining District ⓘ Chisholm Claims (Shamrock Mine; Mrs. Dewey; Little Jean)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Meadows Mining District ⓘ Chisholm (Shamrock Mine; Mrs. Dewey; Little Jean)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Jefferson Co. Madras ⓘ Richardson Ranch	[Opal-A var: Opal-AN] K. Volkman personal collection
ⓘ Priday Polka Dot Beds	[Opal] Occurs inside the Thunder Eggs
ⓘ Round Butte Cinder Pit	[Opal] Aidan Cerenzie Collection
Klamath Co. ⓘ Oregon Technical Institute Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Summit Rock	[Opal-A var: Opal-AN] Kleck. W. D. (1970): Cavity Minerals At Summit Rock. American Mineralogist. 55, 1396-1404
Lake Co. Christmas Valley ⓘ Christmas Valley pit	[Opal] MRDS file #10225715.
Glass Buttes ⓘ Cascade Property	[Opal] BROOKS, H. C. (1963) QUICKSILVER IN OREGON: OREGON DEPT. OF GEOLOGY AND MINERAL INDUSTRIES, BULLETIN 55; 174.
ⓘ Glass Buttes Mine	[Opal] BROOKS, H. C. (1963) QUICKSILVER IN OREGON: OREGON DEPT. OF GEOLOGY AND MINERAL INDUSTRIES, BULLETIN 55; 173.
ⓘ Hart Mountain	[Opal] Dake, 1956. NW Gem Trails, 2nd ed.
ⓘ West Face Occurrence	[Opal] Steve Ewens collection
ⓘ Juniper Ridge Opal Mine	[Opal] Extra Lapis - English No. 10 Opal
Plush ⓘ Oregon Sunstone public collection area	[Opal-A var: Opal-AN] O'Neal, C. (2013), Field collection and visual analysis of the Oregon Sunstone deposits near Plush, Lake County, Oregon; March.
ⓘ Spectrum Mine	[Opal-A var: Opal-AN] O'Neal, C. (2013), Field collection and visual analysis of the Oregon Sunstone deposits near Plush, Lake County, Oregon; March.
Quartz Mountain ⓘ Madera Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Quartz Mountain Gold Deposit (Fremont; Quartz Mountain Property)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ School Creek Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Lane Co. Black Butte Mining District ⓘ Hobart Butte	[Opal] From the labelled Byron Weissberg PhD collection.
Malheur Co. ⓘ Brandon Occurrence (Quartz Mtn.; Glassy Butte)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Lake Owyhee State Park ⓘ Owyhee Dam	[Opal] No reference listed
Opalite Mining District (McDermitt Mining District) ⓘ Aurora Uranium Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; Nevada Bureau of Mines and Geology NBMG Open-File Report 96-3 By Stephen B. Castor, Christopher D. Henry, Lisa A. Shevenell
ⓘ Rome Zeolite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Sheaville Zeolite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Succor Creek	[Opal] Dake, H,C. (1956) Northwest Gem Trails: A field guide for the gem hunter, the mineral collector, and the tourist., 2nd ed., 80 pages.
Marion Co. Santiam Mining District (Elkhorn Mining District) ⓘ Breitenbush Hot Springs Cinnabar Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Morrow Co. ⓘ Opal Butte	[Opal-A var: Opal-AN] USGS
Pennsylvania Adams Co. Gettysburg ⓘ Teeter Quarry (Teeters Quarry; Valley Quarry; John S. Teeter and Sons Co. Quarry; Gettysburg Quarry; H.T. Campbell's Teeter's Quarry)	[Opal] Rocks & Minerals 81:229-234
Berks Co. Birdsboro Gibraltar ⓘ Dyer Quarry	[Opal-A var: Opal-AN] The Mineralogy of Pennsylvania 1966-1975; Robert C. Smith II ; pg. 53
Delaware Co. Springfield Township ⓘ Leiper's Quarry	[Opal] Rocks & Min.: 59:109-120 & 62:176-178.
Lycoming Co. Franklin Township ⓘ McCauley prospect 17	[Opal] Smith and Hoff (1984)
Philadelphia Co. Philadelphia Frankford ⓘ Barber's Quarry	[Opal-A var: Opal-AN] Mineralogy of Pennsylvania-1922; Samuel S. Gordon, pg. 229
ⓘ Peter's Quarry	[Opal-A var: Opal-AN] Mineralogy of Pennsylvania-1922; Samuel S. Gordon, pg. 229
Germantown ⓘ Wayne Junction Quarry	[Opal-A var: Opal-AN] Mineralogy of Pennsylvania, S. G. Gordon - 1922, p. 226.
ⓘ Wissahickon Valley	[Opal-A var: Opal-AN] Gordon, 1922. The Mineralogy of Pennsylvania
York Co. ⓘ York	[Opal] Gems and Minerals of America- Jay Ellis Ransom-1974
Rhode Island Bristol County Barrington ⓘ Bay Spring quarries	[Opal]
Providence County Burrillville Oakland ⓘ State Route 102 road cut	[Opal-A var: Opal-AN] Miller, 1971. RI Minerals & Their Locations
Cumberland ⓘ Beacon Pole Hill quarry	[Opal] Museum of Natural History, Roger Williams Park, Providence, R.I. G3834 6070
ⓘ Diamond Hill Granite Company quarry (Catamint Hill quarry; Calumet Hill quarry)	[Opal] Miller, C. E. (1971) Rhode Island Minerals and Their Locations, O. D. Hermes, Ed., University of Rhode Island, Kingston
ⓘ Grants Mills	[Opal-A var: Opal-AN] Gems & Minerals 395 (August, 1970).
ⓘ Iron Mine Hill quarry	[Opal] Miller, C.E. (1972) Minerals of Rhode Island. Department of Geology, University of Rhode Island, 83 pages.
ⓘ Sneech Pond copper mines (Copper Mine Hill)	[Opal-A var: Opal-AN] Eckert, Allan W. (1997): The World of Opals, p. 346.
East Providence ⓘ Ide's Ledge quarry	[Opal] No reference listed
Johnston ⓘ Interstate 295 / US Route 6 road cuts	[Opal-A var: Opal-AN] George, Gilbert (1972). Latest Finds at Rhode Island Road Cuts(Micromounters of New England no. 17, Feb. 1972).
Lincoln Lime Rock ⓘ Conklin Quarry	[Opal] Rocks & Minerals (1986): 61: 286-289
Washington County New Shoreham Block Island ⓘ Black Rock Point	[Amber]
South Carolina Charleston County ⓘ Charleston	[Amber]
ⓘ Fairfield County	[Opal] Speer, J.Alexander.,(1987) Evolution of magmatic AFM mineral assemblages in granitoid rocks :The hornblende+melt = biotite reaction in the Liberty Hill pluton, South Carolina :American Mineralogist,Vol. 72, pg. 863-878 ,1987
ⓘ Kershaw County	[Opal] Speer, J.Alexander.,(1987) Evolution of magmatic AFM mineral assemblages in granitoid rocks :The hornblende+melt = biotite reaction in the Liberty Hill pluton, South Carolina :American Mineralogist,Vol. 72, pg. 863-878 ,1987
ⓘ Lancaster County	[Opal] Speer, J.Alexander.,(1987) Evolution of magmatic AFM mineral assemblages in granitoid rocks :The hornblende+melt = biotite reaction in the Liberty Hill pluton, South Carolina :American Mineralogist,Vol. 72, pg. 863-878 ,1987
South Dakota ⓘ Campbell Co.	[Opal] Jay Ellis Ransom, 1974,Gems and Minerals of America
ⓘ Corson Co.	[Opal] Jay Ellis Ransom, 1974,Gems and Minerals of America
Custer Co. Custer Mining District Fourmile ⓘ Helen Beryl Mine	[Opal-A var: Opal-AN] Rocks & Minerals: 60: 117.
Needles ⓘ November Mine	[Opal] R&M 75:3 pp 156-169
Lawrence Co. Bald Mountain Mining District (Portland Mining District) Annie Creek ⓘ Davier Mine	[Opal] R&M 75:3 pp 156-169
ⓘ Wharf Mine	[Opal] PEDRAZA ROJAS, Johana Margaret, HOLLEY, Elizabeth, WENDLANDT, Richard, PFAFF, Katharina and RASMUSSEN, Hans (2016) Geologic Control on Alteration and Mineralization of the Wharf Mine, South Dakota. Geological Society of America Abstracts with Programs. Vol. 48, No. 7
Pennington Co. Harney City ⓘ Wood Tin mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Keystone Mining District Keystone ⓘ Barker-Ferguson Mine	[Opal] Smith, A.E., Fritzsch, E. (2000) South Dakota. Rocks & Minerals: 75(3): 156-169.
ⓘ Etta Mine	[Opal] Rocks & Minerals: 67(6): 380-388.; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Peerless Mine (Monitor; Monarch; Protector)	[Opal] Černý, P., Roberts, W.L., Ercit, T.S., Chapman, R. (1985) Wodginite and associated oxide minerals from the Peerless Pegmatite, Pennington County, South Dakota. American Mineralogist: 70(9-10): 1044–1049.
Scenic ⓘ Bear Creek Basin	[Opal] R&M 75:3 pp 156-169
ⓘ Scenic south area (2)	[Opal] SDSMT Bull 18 Roberts and Rapp "Mineralogy of the Black Hills"
Todd Co. ⓘ Mission	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
ⓘ Walworth Co.	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
Tennessee Bradley Co. ⓘ Black Fox Quarry	[Opal] U.S. Geological Survey,2005,Mineral Resources Data System: U.S. Geological Survey,Reston,Virginia
Hardin Co. ⓘ Coffee Bluff	[Amber] Zeitner ,1968. Appalachian Mineral & Gem Trails
Overton Co. ⓘ Pilot Knob Prospect	[Opal] Travis A. Paris (2011) Tennessee mineral locality index. Rocks & Minerals, 86, #4, 300-328.
Texas Armstrong Co. ⓘ Unknown Diatomite Deposit	[Opal] U.S. Geological Survey,2005,Mineral Resources Data System ;U.S. Geological Survey, Reston, Virginia
Brewster County Alpine ⓘ Ritchie Ranch	[Opal] www.austingemandmineral.org
ⓘ Woodward Ranch	[Opal] Smith, A.E. (2016) Texas Mineral Locality Index. Rocks & Minerals, 66(3), 196-224. http://www.omsinc.org/archives/Ore-cutts_Jan04.pdf
Christmas Mountains ⓘ Ferandes Mine (Destolin Mine; Scott claims; Gatlin claims)	[Opal] R&M 66:3 pp 196-224
Davis Mountains ⓘ Cathedral Mountain quadrangle	[Opal] R&M 66:3 pp 196-224
ⓘ Haleys Peak	[Opal] Dorothy M. Schlegal (1957) Gem Stones of the United States : USGS Bulletin 1042-G
ⓘ Terlingua Creek	[Amber] R&M 66:3 pp 196-224
Burnet Co. ⓘ Cactus Jack pegmatite	[Opal-A var: Opal-AN] Personally collected by Franklin Roberts
ⓘ Milwhite Quarry	[Opal] U.S. Geological Survey,2005,Mineral Resources Data System :U.S. Geological Survey,Reston, Virginia
Duval Co. Freer ⓘ Cedro Hill	[Opal] Smith, A.E. (2016) Texas Mineral Locality Index. Rocks & Minerals, 66(3), 196-224. R. Maxwell (1962) Mineral Resources of South Texas. UT Bureau of Economic Geology Report of Investigations No. 43
ⓘ Fayette Co.	[Opal] R&M 66:3 pp 196-224
ⓘ Hockley Co.	[Opal] USGS National Geochemical Database :Rocks -File D183365
Hudspeth Co. Quitman Mountains ⓘ Granite Hill prospect	[Opal] R&M 66:3 pp 196-224
ⓘ Silver King Mine (Big Gulch Mine)	[Opal] R&M 66:3 pp 196-224
Sierra Blanca Peaks ⓘ Little Blanca Mountain prospects	[Opal] Am Min 72:1122-1130
Jeff Davis Co. Davis Mountains ⓘ Medley's White Mountain	[Opal] R&M 66:3 pp 196-224
Karnes Co. ⓘ Karnes Uranium Mining District	[Opal] www.wma-minelife.com/uranium/papers/karnes.htm; Cherepon, Alan J., Minerals of the Karnes Uranium District - The Franklin of Texas.
Live Oak Co. Ray Point Mining District ⓘ McLean mine	[Opal] Econ Geol (1986) 81:131-142
Llano Co. ⓘ Blount Mountain (Stewart property)	[Opal] R&M 66:3 pp 196-224
Bluffton ⓘ Baringer Hill Mine	[Opal] Smith, A.E. (1991) Texas Mineral Locality Index. Rocks and Minerals: 66(3): 196-224.
Kingsland Granite Company Quarry (Petrick Quarry) ⓘ Petrick pegmatite	[Opal-A var: Opal-AN] Self-collected by Franklin Roberts.
ⓘ Rode Ranch pegmatite	[Opal-A var: Opal-AN] Economic Geology; November 1964; v. 59; no. 7; American Mineralogist 50:284
ⓘ Six Mile quarry	[Opal] R&M 66:3 pp 196-224
Maverick Co. ⓘ Eagle Pass	[Amber] BEG Rept Invest 42
ⓘ Presidio Co.	[Opal-A var: Opal-AN] Roselle M. Girard (1964) Texas Rocks and Minerals : Bureau of Economic Geology Guidebook No.6
ⓘ Mammoth Mine	[Opal] R&M 66:3 pp 196-224
Sutton Co. Edwards Plateau ⓘ Caverns of Sonora (Mayfield Cave)	[Opal] Onac, B., Veni, G. & White, W. B. (2001). Depositional environment for metatyuyamunite and related minerals from Caverns of Sonora, TX (USA). European Journal of Mineralogy, 13(1), 135-143.
U.S. Virgin Islands St Croix ⓘ Judith Fancy Formation ?	[Opal] Am Min 50:752
Utah Beaver County Beaver ⓘ Unnamed Opal-AN occurrence [1]	[Opal-A var: Opal-AN] UGMS Bull 117 Minerals and Mineral Localities of Utah
Lincoln Mining District ⓘ Creole Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Milford	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Hyalite occurrence	[Opal-A var: Opal-AN] Rick Dalrymple
Roosevelt Hot Springs Mining District ⓘ Roosevelt Hot Springs	[Opal] Petersen, C.A. (1975) Geology and geothermal potential of the Roosevelt Hot Springs area, Beaver County, Utah. Thesis for Master of Science, University of Utah: 49.
ⓘ Roosevelt Hot Springs Geothermal Resource Area	[Opal] Nielson, D. L.; Sibbett, B. S.; McKinney, D. B.; Hulen, J. B.; Moore, J. N. & Samberg, S. M. (1978) Geology of Roosevelt Hot Springs KGRA, Beaver County, Utah. Earth Science Laboratory, University of Utah Research Institute.
ⓘ Ruby Violet claims (Violet claims; Violet Mine; Red Emerald Mine; Harris Mine)	[Opal] Nassau K., Wood D.L. (1968) An examination of red beryl from Utah. The American Mineralogist, 53: 801-806.
San Francisco Mining District Frisco ⓘ Horn Silver Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
San Francisco Mountains ⓘ Brimstone Mound	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Box Elder County Crater Island Crater Island Mining District ⓘ Pass Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Hogup Mountains ⓘ Kelton Butte Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Peplin Flats Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Daggett County Red Creek (Browns Park) ⓘ Yellow Canary Uranium deposit	[Opal-A var: Opal-AN] UGMS Bull 117 Minerals and Mineral Localities of Utah; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Uinta Mountains ⓘ Red Creek complex	[Opal-A var: Opal-AN] UGMS Bull 117 Minerals and Mineral Localities of Utah
East Tintic Mountains ⓘ Tintic Mining District	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Emery County ⓘ Temple Mountain Mining District	[Opal-A var: Opal-AN] Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 992, 1056.; DANA R. KELLEY AND PAUL F. KERR (1958) URANO-ORGANIC ORE AT TEMPLE MOUNTAIN, UTAH. BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 69. PP. 701-756.
Garfield County Hatch ⓘ Hillsdale Diatomite Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Spry Mining District ⓘ Veater Mercury Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Grand County ⓘ Cisco	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Iron County Gold Springs Mining District (Hamlin Valley) ⓘ CIMA (Marietta; Stratton) Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Juab County San Pitch Mountains ⓘ Orme property	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Thomas Range	[Opal] T. Kennedy collection
ⓘ Buena no. 1 claim	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Garnet Basin	[Opal] J. Holfert, W. Mroch, J. Fuller (1996) A Field Guide to Topaz and Associated Minerals of the Thomas Range, Utah (Topaz Mountain) Vol I HM Publishing 103pp
ⓘ Spor Mountain Mining District	[Opal] Rockpick Legend
ⓘ Nonella prospect	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah; Thurston, W. R.; Staatz, M. H.; Cox, D. C. (1954) Fluorspar deposits of Utah. USGS Bulletin: 1005
Starvation Canyon ⓘ Holfertite pit	[Opal] Rick Dalrymple Collection
ⓘ Topaz Mountain	[Opal-A var: Opal-AN] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Autunite No. 8 claim	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah; Am.Min.: 45: 39-52
ⓘ The Cove (Topaz Valley)	[Opal-A var: Opal-AN] Greg Slak specimen
Millard County House Range ⓘ Diatomaceous Earth (MRDS - 10010745)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Piute County Antelope Range Henry Mining District (Durkee Mining District) ⓘ Prospector Mine (Sugar Daddy Incline)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Marysvale Mining District ⓘ J & L Alunite Mine	[Opal-A var: Opal-AN] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Silica Hills	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Salt Lake County Bingham Mining District ⓘ Bingham Canyon Mine	[Opal] North, Jerry (2010) Displays of Nature : History, Minerals & Crystals of Utah's Bingham Canyon Copper Mine.
ⓘ Galena Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ Old Jordan Mine 1863 (U. S. Mining Company 1899)	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
San Juan County White Canyon Mining District ⓘ Gonaway-North Point claim	[Opal] USGS: Geological Survey Circular 217
Sevier County ⓘ Aurora	[Opal-A var: Opal-AN]
ⓘ Fish Lake	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
Tooele County Bingham Mining District ⓘ Carr Fork Mine	[Opal] U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Carr Fork Mine (Utah Apex Pre 1947)	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Gold Hill Mining District (Clifton Mining District) Clifton ⓘ Monocco Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Wilson Consolidated Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Gold Hill ⓘ Alvarado Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Gold Hill Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah
ⓘ U.S. Mine	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Gold Hill Wash Prospect	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Murphy-Lucky Strike Prospects	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
ⓘ Undine Mine	[Opal] UGMS Bull 117 Minerals and Mineral Localities of Utah; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Grassy Mountains ⓘ Diatom Gulch Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Lakeside Mining District ⓘ Delle Diatomaceous Earth Occurrence	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Stansbury Island ⓘ Diatomaceous Earth prospect	[Opal] Tripp, B.T. (1980), On-site Investigation, Utah Geologic and Mineral Survey; USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10087547.
Vermont Orleans & Lamoille Cos. Lowell & Eden ⓘ Belvidere Mountain Quarries	[Opal] Van King
Windham County ⓘ Guilford	[Opal] Morrill & Chaffee, 1957. VT Mines & Mineral Localities
Virginia Albemarle Co. Stony Point ⓘ Stony Point Mine	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Amelia Co. ⓘ Amelia (Amelia Court House)	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Winterham ⓘ Morefield Mine (Morefield pegmatite)	[Opal-A var: Opal-AN] Mike Dennis specimens
Augusta Co. Parnassus ⓘ Buck Hill	[Opal] Rocks & Minerals 84:352-362.
Botetourt Co. Buchanan ⓘ James River Hydrate Quarries	[Opal] Rocks & Min.:60:165.
Clarke Co. ⓘ Berryville Mine (Keneagy Ore Bank)	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Culpeper Co. Mitchell ⓘ Cedar Mountain Stone Corp. Quarry (A. H. Smith quarry)	[Opal-A var: Opal-AN]
Rapidan ⓘ Unnamed Quarry	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
ⓘ Fairfax Co.	[Opal-A var: Opal-AN] Gems and Minerals of America-Jay Ellis Ransom-1974
Culpeper Basin ⓘ Centreville	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Hanover Co. ⓘ Ashland	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Henrico Co. Richmond ⓘ Forest Hill Park	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
Henry Co. ⓘ Axton	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
King George Co. ⓘ Greenlaws Wharf	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Loudoun Co. Conklin ⓘ Bull Run Quarry	[Opal-A var: Opal-AN] Dietrich, R.V. (1990) Minerals of Virginia, 1990. Department of Mines, Minerals and Energy, Richmond, Virginia: 474 pp.
Leesburg ⓘ Old Goose Creek Quarry	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
ⓘ Virginia Trap Rock Quarry (Goose Creek quarry)	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
Louisa Co. Gold-Pyrite Belt ⓘ Allah Cooper Mine (Alley-Cooper Mine; Ali Cooper Mine; Valcooper Mine)	[Opal] Kearns, Lance E.; Dunn, Michael D. (2008) Vauquelinite & Mottramite from a New Locality: Louisa County, Virginia. Mineral News: 24(8): 1-6.
Lunenburg Co. ⓘ Kenbridge Quarry	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
ⓘ Powhatan Co.	[Opal] Holland, J. D. (2006) Virginia Lithic Types: Chert, quartzite and Others. Quarterly Bulletin Virginia Archeological Society 61:137-152
ⓘ Colman Jones Farm	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Flat Rock ⓘ Herbb No. 2 Mine	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
Prince William Co. Manassas ⓘ Vulcan Materials Company Crushed Stone Quarry (Manassas Quarry)	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Richmond (City) ⓘ Carter Wharf	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Roanoke Co. ⓘ US highway 220 roadcut	[Opal-A var: Opal-AN] Minerals of Virginia 1990 by R. V. Dietrich
Wise Co. ⓘ Coeburn	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
ⓘ Norton	[Opal] Minerals of Virginia 1990 by R. V. Dietrich
Washington Benton Co. ⓘ Hanford	[Opal] Tschernich, R. (1992): Zeolites of the World, p. 120
Chelan Co. Wenatchee Mining District ⓘ Wenatchee	[Amber] Cannon, B. (1975): Minerals of Washington, p.40
Clark Co. Orchards ⓘ Livingston Quarry	[Opal] Zeolites of the World by Rudy Tschernich pg. 481; Bill Tompkins collection
Douglas Co. ⓘ Rock Island Dam	[Opal] Tschernich (1991): Zeolites of Washington State. Rock & Minerals, 66(4); American Mineralogist, Volume 67, pages 799-803, 1982
Grant Co. Coulee City ⓘ ~~Coulee City Marina~~	[Opal-A var: Opal-AN] T Douglas Schonewald Collection
ⓘ State Route 17 road cut [1]	[Opal] T Douglas Schonewald Collection
ⓘ State Route 17 road cuts [2]	[Opal-A var: Opal-AN] Personally collected by T Douglas Schonewald, catalog: MI-2016-0067, MinID: 19M-UUF
Frenchman Hills ⓘ Diatomite Mines (Diatomite Pit South)	[Opal]
Mattawa ⓘ Saddle Mountain	[Opal] Minerals of Washington, Bart Cannon, 1975
Quincy ⓘ Diatomite Mines (Diatomite Pit North)	[Opal] Menicucci, A. J. (2010). Paleolimnology and paleontology of the Miocene Quincy Diatomite deposit. University of Nevada, Reno.
Warden ⓘ Perch Point-Potholes Reservoir (Medicare Beach)	[Opal-A var: Opal-AN] T Douglas Schonewald Collection
ⓘ State Route 262 roadcuts	[Opal-A var: Opal-AN] T Douglas Schonewald Collection
King Co. Snoqualmie Mining District ⓘ Denny Mountain	[Opal] Karl Volkman Personal Collection
ⓘ Denny Gulch	[Opal] John Lindell Collection
ⓘ Tiger Mountain	[Amber] Cannon, B. (1975): Minerals of Washington, p.41; Mustoe, G. E. (1985). Eocene amber from the Pacific coast of North America. Geological Society of America Bulletin, 96(12), 1530-1536
Kittitas Co. ⓘ Vantage area	[Opal] http://www.mineralcouncil.org/
Klickitat Co. Roosevelt ⓘ Roosevelt area	[Opal] Minerals of Washington, Bart Cannon, 1975
Lewis Co. Morton Mining District Glenoma ⓘ Barnum-McDonnell Mine	[Opal] Cannon, B. (1975): Minerals of Washington, p.74
ⓘ Lytle-Lynch Mine (Charlotte Mine; Kropolis Mine; Lytle Mine; Lynch Mine)	[Opal] Cannon, B. (1975): Minerals of Washington, p.74
ⓘ Roy Mine (Fisher Mine; Morton Mine; Gillispie Mine)	[Opal] Cannon, B. (1975): Minerals of Washington, p.74
Morton ⓘ Spencer Mine	[Opal] Minerals of Washington, Bart Cannon, 1975
Lincoln Co. ⓘ Mondovi	[Opal-A var: Opal-AN] Dake, 1956. NW Gem Trails, 2nd ed.
ⓘ Mount Rainier National Park	[Opal] Rye, R. O., Breit, G. N., & Zimbelman, D. R. (2003). Preliminary mineralogic and stable isotope studies of altered summit and flank rocks and Osceola Mudflow deposits on Mount Rainier, Washington. US Department of the Interior, US Geological Survey.
Okanogan Co. Golden Horn Batholith ⓘ Washington Pass	[Opal] John Lindell field collected specimens
Skagit Co. ⓘ Mount Vernon Mine	[Opal] American Mineralogist 28:257-271; S.W. Hobbs and W.T. Pecora (1941) Strategic minerals investigations, 1941, short papers and preliminary reports. Nickel-gold deposit near Mount Vernon, Skagit County, Washington. USGS Bulletin 931-D
Spokane Co. ⓘ Spokane	[Opal-A var: Opal-AN] http://www.mindat.org/forum.php?pm,0,page=read,folder_id=inbox,pm_id=39097
ⓘ City Quarry	[Opal] Rocks & Min.:8:30.
Walla Walla Co. Dixie ⓘ Dixie Road Cut Siderite Occurrence	[Opal] Jared Goguen
Whitman Co. ⓘ Moses (Clarkston)	[Opal] Micro Probe Volume VII Number 9 Spring 1994
Pullman ⓘ Pullman area quarries	[Opal] Minerals of Washington, Bart Cannon, 1975
Whelan ⓘ Unnamed opal occurrence	[Opal] Minerals of Washington, Bart Cannon, 1975
Yakima Co. ⓘ Chinook Pass	[Opal-A var: Opal-AN] T Douglas Schonewald Collection
West Virginia Monongalia Co. ⓘ Coopers Rock	[Opal] West Virginia Geological & Economic Survey
Wisconsin Dodge Co. Iron Ridge Mining District (Neda Iron Mining District) ⓘ Iron Ridge Mines	[Opal] Hawley, J. & A. Bevan (1934) Mineralogy and genesis of the Mayville iron ore of Wisconsin: american Mineralogist: 19 (11): 493- 514.
ⓘ Iron Ridge Mine (Neda Mine; Oliver Mine)	[Opal] Hawley, J. & A. Bevan (1934) Mineralogy and genesis of the Mayville iron ore of Wisconsin: american Mineralogist: 19 (11): 493- 514.
ⓘ Mayville Shaft Mine	[Opal] Hawley, J. & A. Bevan (1934) Mineralogy and genesis of the Mayville iron ore of Wisconsin: american Mineralogist: 19 (11): 493- 514.
Florence Co. Fern Pine River pegmatites ⓘ Animikie Red Ace pegmatite	[Opal-A var: Opal-AN] Sirbescu, M. L. C., E. E. Hartwick, E.E., & J. J. Student (2008): Rapid crystallization of the Animikie Red Ace Pegmatite, Florence county, northeastern Wisconsin: inclusion microthermometry and conductive-cooling modeling. Contributions to Mineralogy and Petrology: 156: 289-305.
Marathon Co. ⓘ Wausau Intrusive Complex	[Opal-A var: Opal-AN] [MinRec 12:95]; Rocks and Minerals, (1987) 62:188-195
ⓘ "Rotten granite" quarries	[Opal] Rocks & Min.: 62: 188.
ⓘ Wyoming	[Amber] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.
ⓘ Albany County	[Opal] Jay Ellis Ransom,1974, Gems and Minerals of America
Campbell County ⓘ Wyodak Coal seams	[Amber] Rocks & Minerals 76:383
Carbon County ⓘ Anderson Ranch	[Opal] Personal Collection of Matthew Neuzil
ⓘ Hanna Basin	[Amber] Rocks & Minerals 76:384
Crook County ⓘ Bear Lodge alkaline igneous complex	[Opal] Van Rythoven, A. D., Pfaff, K., & Clark, J. G. (2020). Use of QEMSCAN® to characterize oxidized REE ore from the Bear Lodge carbonatite, Wyoming, USA. Ore and Energy Resource Geology, 2, 100005.
Fremont County ⓘ Lucky MC mine (Lucky Mac)	[Opal] Am Min 51:1567-1578
ⓘ Vitro Uranium Open Pit	[Opal] U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
Natrona County ⓘ Angel Agates occurrence	[Opal] Wyoming Agates. Jade State News Volume 2019, Issue #2
ⓘ Park County	[Opal] Yale Peabody Museum
Grand Canyon of the Yellowstone ⓘ Seven Mile Well	[Opal] 2009 Portland GSA Annual Meeting (18-21 October 2009) Paper No. 26-23; Phillips, A. R., Larson, P. B., John, D. A., & Pauley, B. M. (2008, December). Hydrothermal Quartz Oxygen Isotope Ratios in Altered Post-Collapse Rhyolite at Sevenmile Hole, Grand Canyon of the Yellowstone River, Yellowstone National Park, WY. In AGU Fall Meeting Abstracts.
Teton County ⓘ Jackson Hole area	[Amber] Rocks & Minerals 76:390
Moran ⓘ Glade Creek	[Opal-A var: Opal-AN] Iddings, J P and S L Penfield "The Minerals in Hollow Spherulites of Rhyolite from Glade Creek, Wyoming" American Journal of Science Vol 42 No 247 (1892) pp. 39-46
ⓘ Yellowstone National Park	[Opal] Economic Geology; November 1972; v. 67; no. 7; p. 965-972

Uzbekistan
Fergana Region Uzbekistan District ⓘ Shorsu deposit (Shor-Su deposit)	[Opal] Uklonskiy, A.S. [Уклонский, А.С.] (1964) Geochemistry of native sulphur [К геохимии самородной серы]. Uzbek Geological Journal [Uzbekskiy Geologicheskiy Zhurnal, Узбекский геологический журнал], 6, 5-10; Uklonskiy, A.S. [Уклонский, А.С.] (1982) Geochemistry of native sulphur [К геохимии самородной серы]. In: Problems of mineralogy and geochemistry. Selected papers [Проблемы минералогии и геохимии. Избранные труды]. Uzbek SSR Branch, Academy of Sciences Press [Издательство "Фан" Узбекской ССР], Tashkent, 66-71.
Navoiy Central Kyzylkum Region Bukantau Mountains ⓘ Alisai Mn deposit	[Opal] Pechenkin, V.G., and Pechenkin, I.G. (2005): Lithology and Mineral Resources 40(5), 462-471.
Lyavlyakan-Beshkak ore field ⓘ Beshkak U deposit	[Opal] Solodov, I.N., Nesterova, M.V., Shugina, G.A., Ganina, N.I., Shulik, L.S., and Solodov, D.I. (2001): Lithology and Mineral Resources 36(1), 43-62.
ⓘ Sugraly U deposit	[Opal] Franz J Dahlkamp (2009) Uranium Deposits of the World: Asia (Springer Reference)
Tashkent Region Ohangaron District ⓘ Kurgashinkan Mine	[Opal] Golovanov, I. M.: O nachodke chantita v mestorožděnii Kurgašinkan (UzSSR). Doklady Akademii nauk SSSR, 1959, tom. 124, no. 2, s. 398 - 401.

Vanuatu
Tanna Island ⓘ Yasur	[Opal-A var: Opal-AN] R. Martin personal collection

Venezuela
Amazonas ⓘ Cerro Autana Cave	[Opal] Urbani, F. (1996) Venezuelan cave minerals: a review. Boletín de la Sociedad Venezolana de Espeleología, No.30, 1-13.
Bolívar Auyán-tepui (Auyán-tepuy; Ayan Tepui) ⓘ Cueva Guacamaya	[Opal] Sauro, F., De Waele, J., Forti, P., Ermanno, G., Vergara, F. (2013) Speleogenesi e speleotemi di opale della Cueva Guacamaya, Auyan Tepui, Gran Sabana, Venezuela. In: Cucchi, F., Gudi, P. (eds.), Atti del XXI Congresso Nazionale di Speleologia “Diffusione delle conoscenze”, Sessione Attività di esplorazione e ricerca. Trieste 2-5 giugno 2011. Edizioni Università di Trieste, Trieste, 461-469.
ⓘ Imawarì Yeuta cave	[Opal] Sauro, F., De Vivo, A., Vergara, F., De Waele, J. (2013) Imawarì Yeuta: a new giant cave system in the quartz sandstones of the Auyan Tepui, Bolivar state, Venezuela. Proceedings of the 16th International Congress of Speleology, 2, 19-27.
ⓘ Sima Aonda Superior	[Opal] BOLETÍN INFORMATIVO DE LA COMISIÓN DE GEOESPELEOLOGÍA (Federación Espeleológica de América Latina y el Caribe -FEALC-) No. 13, Octubre 1999
Chimantá Massif (Chimantha Massif) ⓘ Akopan-Dal Cin cave system	[Opal] Galli, E., Brigatti, M.F., Malferrari, D., Sauro, F., De Waele, J. (2013): Rossiantonite, Al3(PO4)(SO4)2(OH)2(H2O)10•4H2O, a new hydrated aluminum phosphate-sulfate mineral from Chimanta massif, Venezuela: Description and crystal structure. American Mineralogist, 98, 1906-1913.
ⓘ Roraima Sur Cave System	[Opal] Franco Urbani, Bogdan P. Onac (2017) A Native Aluminum Occurrence in Roraima South Cave, Venezuela. In 17th International Congress of Speleology (No. I, pp. 272). Australian Speleological Federation Inc.
ⓘ Cojedes	[Opal] Charlie Smith Collection
Miranda ⓘ Cueva de Baruta	[Opal] Urbani, F. (1996) Venezuelan cave minerals: a review. Boletín de la Sociedad Venezolana de Espeleología, No.30, 1-13.
ⓘ Unspecified Caves	[Opal] Franco Urbani (2009) Venezuelan Cave Minerals: Second Review. Mineralogy 1 2009 ICS Proceedings. In 15th International Congress of Speleology. p 345

Vietnam
Bà Rịa-Vũng Tàu Province Đất Đỏ District ⓘ Nui Thom	[Opal] Mario Lazzerini Denchi Collection.
Lâm Đồng Province Don Duong District Lac Xuan ⓘ Kankin quarry	[Opal] "Mario Lazzerini Denchi" Collection

Zimbabwe
Matabeleland North Hwange District Dinde ⓘ Unnamed opal showing	[Opal] Wolfgang Hampel, site visit July 2014

Mars
Aeolis quadrangle Gale Crater Aeolis Mons (Mount Sharp) ⓘ Lower Mt. Sharp	[Opal] Milliken, R.E., Hurowitz, J.A., Bish, D.L., Grotzinger, J.P., Wiens, R. (2016): The chemical and mineralogical stratigraphy of Lower Mt. Sharp: relating rover observations to orbital predictions. 47th Lunar and Planetary Science Conference: pdf no. 1495
ⓘ Marias Pass ?	[Opal] Morris, R.V., Vaniman, D.T., Blake, D.F., Gellert, R., Chipera, S.J., Rampe, E.B., Ming, D.W., Morrison, S.M., Downs, R.T., Treiman, A.H., Yen, A.S., Grotzinger, J.P., Achilles, C.N., Bristow, T.F., Crisp, J.A., Des Marais, D.J., Farmer, J.D., Fendrich, K.V., Frydenvang, J., Graff, T.G., Morookian, J.-M., Stolper, E.M., Schwenzer, S.P. (2016) Silicic volcanism on Mars evidenced by tridymite in high-SiO2 sedimentary rock at Gale crater. Proceedings of the National Academy of Sciences of the United States of America (online-published). doi: 10.1073/pnas.1607098113 .
Oxia Palus quadrangle ⓘ Mawrth Vallis ?	[Opal] Bishop, J.L., Noe Dobrea, E.Z., McKeown, N.K., Parente, M., Ehlmann, B.L., and Michalski, J.R. (2008) Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars. Science, 321, 830–833; Gornitz, V. (2008) Mineral News, 24, #9, 1-2; Gou, S., Yue, Z., Di, K., and Wang, J. (2015) Mineral abundances and different levels of alteration around Mawrth Vallis, Mars. Geoscience Frontiers, 6, 741-758.
Syrtis Major quadrangle ⓘ Jezero Crater ?	[Opal] Horgan, B. H., Anderson, R. B., Dromart, G., Amador, E. S., & Rice, M. S. (2020). The mineral diversity of Jezero crater: Evidence for possible lacustrine carbonates on Mars. Icarus, 339, 113526.
ⓘ Nili Patera ?	[Opal] Sun, V.Z., Milliken, R.E., Robertson, K.M. (2016): Hydrated silica on Mars: relating geologic setting to degree of hydration, crystallinity, and maturity through coupled orbital and laboratory studies. 47th Lunar and Planetary Science Conferene: pdf no. 2461
Valles Marineris ⓘ Juventae Chasma	[Opal] Bishop, J. L., et al. (2009), Mineralogy of Juventae Chasma: Sulfates in the light-toned mounds, mafic minerals in the bedrock, and hydrated silica and hydroxylated ferric sulfate on the plateau, J. Geophys. Res., 114, E00D09, doi:10.1029/2009JE003352, [printed 115(E2), 2010].
Ophir Planum ⓘ Elorza Crater ?	[Opal] Sun, V.Z., Milliken, R.E., Robertson, K.M. (2016) Hydrated silica on Mars: relating geologic setting to degree of hydration, crystallinity, and maturity through coupled orbital and laboratory studies. 47^th Lunar and Planetary Science Conferene: pdf no. 2461.

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