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Jacobsite-Q

A material that is NOT an approved mineral species

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Photos of Jacobsite-Q (12)

Jacobsite-Q Gallery Search Photos of Jacobsite-Q

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Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Jacobsite-Q

Nordmark Odal Field, Filipstad, Värmland County, Sweden

Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Jacobsite-Q

Nordmark Odal Field, Filipstad, Värmland County, Sweden

Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Jacobsite-Q, etc.

Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

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About Jacobsite-QHide

Formula:

Mn²⁺(Fe³⁺,Mn³⁺)₂O₄

From Bosi et al. (2018); type material has Fe³⁺:Mn³⁺ = 2:1.

Colour:

Greenish black, black

Lustre:

Sub-Vitreous, Metallic, Sub-Metallic

Hardness:

6 - 6½

Specific Gravity:

4.85

Crystal System:

Tetragonal

Member of:

Spinel Subgroup > Oxyspinel Group > Spinel Supergroup

First Recorded Locality:

ⓘ Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Dimorph of:

Jacobsite

Isostructural with:

Spinel

A polymorph of jacobsite, termed jacobsite-Q, earlier named iwakiite.
Contains significant octahedrally coordinated Mn³⁺ distorting the crystal structure to tetragonal.

See also α-vredenburgite.

Unique IdentifiersHide

Mindat ID:

2058

Long-form identifier:

mindat:1:1:2058:5

GUID
(UUID V4):

e6f09c7f-baca-4fa9-be21-852534674d74

IMA Classification of Jacobsite-QHide

IMA status notes:

Redefined by the IMA, Renamed by the IMA

IMA Formula:

Mn²⁺Fe³⁺₂O₄

Approval history:

First described as iwakiite by Matsurbara et al. (1979). Redefined as the tetragonal polymorph of jacobsite and renamed as jacobsite-Q by IMA 2018 (Bosi et al. 2018).

Classification of Jacobsite-QHide

Dana 8th ed.:

7.2.6.2

7 : MULTIPLE OXIDES
2 : AB₂X₄

Hey's CIM Ref.:

7.9.14

7 : Oxides and Hydroxides
9 : Oxides of Ti

Physical Properties of Jacobsite-QHide

Lustre:

Sub-Vitreous, Metallic, Sub-Metallic

Transparency:

Opaque

Colour:

Greenish black, black

Comment:

May look completely black, may be iridescent due to surface alteration.

Streak:

black

Hardness:

6 - 6½ on Mohs scale

Tenacity:

Brittle

Cleavage:

None Observed
None

Fracture:

Conchoidal, Sub-Conchoidal

Density:

4.85 g/cm³ (Measured) 4.89 g/cm³ (Calculated)

Optical Data of Jacobsite-QHide

Reflectivity:

Wavelength	R
20 20.0% 19.4%440 19.9% 19.3%460 20.3% 19.5%480 20.4% 19.6%500 20.8% 19.8%520 21.2% 20.1%540 21.4% 20.3%560 21.3% 20.4%580 21.2% 20.1%600 21.0% 20.0%620 20.9% 19.7%640 20.5% 19.6%660 20.4% 19.2%680 20.2% 19.1%nm	20 20.0 19.4440 19.9 19.3460 20.3 19.5480 20.4 19.6500 20.8 19.8520 21.2 20.1540 21.4 20.3560 21.3 20.4580 21.2 20.1600 21.0 20.0620 20.9 19.7640 20.5 19.6660 20.4 19.2680 20.2 19.1%

Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 20 20.0 19.4440 19.9 19.3460 20.3 19.5480 20.4 19.6500 20.8 19.8520 21.2 20.1540 21.4 20.3560 21.3 20.4580 21.2 20.1600 21.0 20.0620 20.9 19.7640 20.5 19.6660 20.4 19.2680 20.2 19.1%.

Colour in reflected light:

olive-gray

Internal Reflections:

none observed

Pleochroism:

Non-pleochroic

Chemistry of Jacobsite-QHide

Mindat Formula:

Mn²⁺(Fe³⁺,Mn³⁺)₂O₄

From Bosi et al. (2018); type material has Fe³⁺:Mn³⁺ = 2:1.

Elements listed:

Fe, Mn, O - search for minerals with similar chemistry

Crystallography of Jacobsite-QHide

Crystal System:

Tetragonal

Class (H-M):

4/mmm (4/m 2/m 2/m) - Ditetragonal Dipyramidal

Space Group:

I4₁/amd

Setting:

I4₁/amd

Cell Parameters:

a = 6.025 Å, c = 8.54 Å

Ratio:

a:c = 1 : 1.417

Unit Cell V:

310.01 Å³ (Calculated from Unit Cell)

Morphology:

Rarely octahedral, usually granular

Twinning:

{101}, similar to hausmannite

Crystal StructureHide

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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure

ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0010983	Jacobsite-Q	Jarosch D (1988) Crystal structure of iwakiite Zeitschrift fur Kristallographie 185 605-605		1988	Gozaisho mine, Fukushima Prefecture, Japan	0	293

CIF Raw Data - click here to close

data_global
_chemical_name_mineral 'Iwakiite'
loop_
_publ_author_name
'Jarosch D'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 185 
_journal_year 1988
_journal_page_first 605
_journal_page_last 605
_publ_section_title
;
 Crystal structure of iwakiite
 Note: coordinates from ICSD, reproduce reported bond lengths
;
_database_code_amcsd 0010983
_chemical_compound_source 'Gozaisho mine, Fukushima Prefecture, Japan'
_chemical_formula_sum 'Mn1.6 Fe1.2 O4'
_cell_length_a 6.025
_cell_length_b 6.025
_cell_length_c 8.539
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 309.971
_exptl_crystal_density_diffrn      4.691
_symmetry_space_group_name_H-M 'I 41/a m d'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/4-y,3/4-x,1/4+z'
  '3/4-y,1/4-x,3/4+z'
  '1/4+y,3/4+x,1/4-z'
  '3/4+y,1/4+x,3/4-z'
  '1/4+y,3/4-x,1/4-z'
  '3/4+y,1/4-x,3/4-z'
  '1/4-y,3/4+x,1/4+z'
  '3/4-y,1/4+x,3/4+z'
  '1/2+x,-y,1/2+z'
  '+x,1/2-y,+z'
  '1/2-x,y,1/2-z'
  '-x,1/2+y,-z'
  '1/2+x,y,1/2-z'
  '+x,1/2+y,-z'
  '1/2-x,-y,1/2+z'
  '-x,1/2-y,+z'
  '1/4+y,1/4+x,3/4+z'
  '3/4+y,3/4+x,1/4+z'
  '1/4-y,1/4-x,3/4-z'
  '3/4-y,3/4-x,1/4-z'
  '1/4-y,1/4+x,3/4-z'
  '3/4-y,3/4+x,1/4-z'
  '1/4+y,1/4-x,3/4+z'
  '3/4+y,3/4-x,1/4+z'
  '-x,y,z'
  '1/2-x,1/2+y,1/2+z'
  'x,-y,-z'
  '1/2+x,1/2-y,1/2-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Mn1   0.00000   0.25000   0.87500   1.00000
Mn2   0.00000   0.50000   0.50000   0.30000
Fe2   0.00000   0.50000   0.50000   0.60000
O   0.00000   0.47560   0.26220   1.00000

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
4.929 Å	(30)
3.016 Å	(40)
2.570 Å	(100)
2.461 Å	(6)
2.135 Å	(16)
2.130 Å	(16)
1.739 Å	(15)
1.640 Å	(30)
1.509 Å	(35)
1.506 Å	(40)
1.299 Å	(10)
1.284 Å	(8)

Comments:

Satoshi MATSUBARA, Akira KATO, Kozo NAGASHIMA (1978) Mineralogical Magazine, v9, pp.383-391.

First Recorded Occurrence of Jacobsite-QHide

First Recorded Locality:

ⓘ Gozaisho mine, Iwaki City, Fukushima Prefecture, Japan

Associated Minerals at First Recorded Locality:

Spessartine	Rhodonite	Rhodochrosite	Quartz	Hematite
Braunite

Synonyms of Jacobsite-QHide

IMA1974-049

Iwakiite

Other Language Names for Jacobsite-QHide

German:Iwakiit

Japanese:磐城鉱

Russian:Ивакиит

Spanish:Iwakiita

Relationship of Jacobsite-Q to other SpeciesHide

Member of:

Spinel Subgroup > Oxyspinel Group > Spinel Supergroup

Other Members of this group:

Chromite	Fe²⁺Cr³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Cochromite	CoCr₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Coulsonite	Fe²⁺V³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Cuprospinel	Cu²⁺Fe³⁺₂O₄	Iso. m3m (4/m 3 2/m)
Dellagiustaite	V²⁺Al₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Deltalumite	(Al_0.67◻_0.33)Al₂O₄	Tet. 4 2m : P4m2
Franklinite	Zn²⁺Fe³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Gahnite	ZnAl₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Galaxite	Mn²⁺Al₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Guite	Co²⁺Co³⁺₂O₄	Iso.
Hausmannite	Mn²⁺Mn³⁺₂O₄	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
Hercynite	Fe²⁺Al₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Hetaerolite	ZnMn₂O₄	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
Jacobsite	Mn²⁺Fe³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Maghemite	(Fe³⁺_0.67◻_0.33)Fe³⁺₂O₄	Iso. 4 3 2 : P4₁ 3 2
Magnesiochromite	MgCr₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Magnesiocoulsonite	MgV₂O₄	Iso. m3m (4/m 3 2/m)
Magnesioferrite	MgFe³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Magnetite	Fe²⁺Fe³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Manganochromite	Mn²⁺Cr₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Nichromite	(Ni,Co,Fe)(Cr,Fe,Al)₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Spinel	MgAl₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Thermaerogenite	CuAl₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Titanomaghemite	(Ti⁴⁺_0.5◻_0.5)Fe³⁺₂O₄	Iso. 4 3 2 : P4₃ 3 2
Trevorite	Ni²⁺Fe³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
UM1994-06-O:AlCo	CoAl₂O₄
Vuorelainenite	Mn²⁺V³⁺₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m
Zincochromite	ZnCr₂O₄	Iso. m3m (4/m 3 2/m) : Fd3m

Common AssociatesHide

Associated Minerals Based on Photo Data:

2 photos of Jacobsite-Q associated with Spessartine	Mn²⁺₃Al₂(SiO₄)₃
1 photo of Jacobsite-Q associated with Adelite	CaMg(AsO₄)(OH)
1 photo of Jacobsite-Q associated with Calcite	CaCO₃
1 photo of Jacobsite-Q associated with Manganophyllite	K(Fe,Mg,Mn)₃AlSi₃O₁₀(OH)₂
1 photo of Jacobsite-Q associated with Diopside	CaMgSi₂O₆
1 photo of Jacobsite-Q associated with Rhodonite	CaMn₃Mn[Si₅O₁₅]

Fluorescence of Jacobsite-QHide

In UV light:

Not fluorescent in UV

Other InformationHide

Magnetism:

Ferrimagnetic

Health Risks:

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

Internet Links for Jacobsite-QHide

mindat.org URL:

https://www.mindat.org/min-2058.html
Please feel free to link to this page.

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References for Jacobsite-QHide

Reference List:

doi.org (n.d.) https://doi.org/10.1127/ejm/2019/0031-2788

Matsubara, Satoshi, Kato, Akira, Nagashima, Kozo (1979) Iwakiite, Mn²⁺(Fe³⁺,Mn³⁺)₂O₄, a new tetragonal spinelloid mineral from the Gozaisho mine, Fukushima Prefecture, Japan. Mineralogical Journal, 9 (7) 383-391 doi:10.2465/minerj.9.383

Jarosch, D. (1988): Crystal structure of iwakiite. Zeitschrift für Kristallographie 185, 605-605.

Bosi, Ferdinando, Biagioni, Cristian, Pasero, Marco (2019) Nomenclature and classification of the spinel supergroup. European Journal of Mineralogy, 31 (1) 183-192 doi:10.1127/ejm/2019/0031-2788

(2023) Jacobsite-Q. Handbook of Mineralogy. Mineralogical Society of America

Localities for Jacobsite-QHide

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

symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- 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.


Austria
Tyrol Lienz District Prägraten am Großvenediger Timmelbach valley ⓘ Wunwand (Wunspitze) ?	Kolitsch et al. (2017)

Japan (FRL)
Fukushima Prefecture Iwaki City ⓘ Gozaisho mine (FRL)	S. Matsubara et al. (1979) +3 other references

Romania
Maramureș County Târgu Lăpuș ⓘ Răzoare	Udubasa et al. (1996) +2 other references

Spain
Andalusia Almería Cuevas del Almanzora ⓘ Golosina mine	Calvo Rebollar et al. (2022)

Sweden
Dalarna County Hedemora Garpenberg ⓘ Garpenberg Norra Mine	Gatedal (n.d.) +1 other reference
Örebro County Hällefors Grythyttan ⓘ Sjögruvan	Holtstam et al. (2001)
Värmland County Filipstad Långban Ore District ⓘ Långban Mine	K.Gatedal
ⓘ Garden dump	Nysten (2014)
Nordmark mining district Jakobsberg ore field ⓘ Jakobsberg Mine	Gatedal (2003)
ⓘ Nordmark Odal Field	Gatedal (2003)
Persberg ore district Pajsberg ⓘ Harstigen Mine	Gatedal (2003) +1 other reference

UK
Wales Gwynedd Aberdaron Rhiw ⓘ Benallt Mine	Cotterell (2008)