rareelement granitic pegmatite fractionation in the Borborema Province, Northeastern Brazil Hartmut Beurlen...Borborema Pegmatitic Province (BPP), northeastern Brazil, is historically important for tantalum mining...to the beryl–columbite phosphate subtype. Electron microprobe analyses (EMPA) of columbite, tapiolite,...n., Cidade Universitária, 50740-530 Recife, PE, Brazil e-mail: beurlen@terra.com.br M. R. R. Da Silva...n., Cidade Universitária, 50740-530 Recife, PE, Brazil M. R. R. Da Silva e-mail: marcelor@ufpe.br R. Thomas