Brumadoite, a new copper tellurate hydrate, from Brumado, Bahia, Brazil

Autor(es)

Atencio, D. ^[1] ; Roberts, A. C. ^[2] ; Matioli, P. A. ^[3] ; Stirling, J. A. R. ^[2] ; Venance, K. E. ^[2] ; Doherty, W. ^[2] ; Stanley, C. J. ^[4] ; Rowe, R. ^[5] ; Carpenter, G. J. C. ^[6] ; Coutinho, J. M. V. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[2] Geol Survey Canada, Ottawa, ON K1A 0E8 - Canada

^[3] Ctr Hist, Museu Ciencias Nat Jose Bonifacio Andrada & Silva, BR-11010260 Santos, SP - Brazil

^[4] Nat Hist Museum, Dept Mineral, London SW7 5BD - England

^[5] Canadian Museum Nat, Ottawa, ON KIP 6P4 - Canada

^[6] Nat Resources Canada, Mat Technol Labs, Ottawa, ON K1A 0G1 - Canada

• Tipo de documento: Artigo Científico
• Fonte: MINERALOGICAL MAGAZINE; v. 72, n. 6, p. 1201-1205, DEC 2008.
• Citações Web of Science: 2

Resumo

Brumadoite, ideally Cu(2)Te(6+)O(4)(OH)(4)center dot 5H(2)O, is a new mineral from Pedra Preta mine, Serra das Eguas, Brumado, Bahia, Brazil. It occurs as microcrystalline aggregates both on and, rarely, pseudomorphous after coarse-grained magnesite, associated with mottramite and quartz. Crystals are platy, subhedral, 1-2 mu m in size. Brumadoite is blue (near RHS 114B), has a pale blue streak and a vitreous lustre. It is transparent to translucent and does not fluoresce. The empirical formula is (Cu(2.90)Pb(0.04)Ca(0.01))(Sigma 2.95) (Te(0.93)(6+)Si(0.05))(Sigma 0.98)O(3.92)(OH)(3.84)center dot 5.24H(2)O. Infrared spectra clearly show both (OH) and H(2)O. Microchemical spot tests using a KI Solution show that brumadoite has tellurium in the 6(+) state. The mineral is monoclinic, P2(1)/m or P2(1). Unit-cell parameters refined from X-ray powder data are a 8.629(2) angstrom, b 5.805(2) angstrom, c 7.654(2) angstrom, beta 103.17(2)degrees, V 373.3(2) angstrom(3), Z = 2. The eight strongest X-ray powder-diffraction lines {[}d in angstrom, (l),(hkl)] are: 8.432,(100),(100); 3.162,(66),((2) over bar 02); 2.385,(27),(220); 2.291,((1) over bar 12),(22); 1.916,(11),(312); 1.666,(14),((4) over bar 22,114); 1.452,(10), (323, 040); 1.450,(10),(422,403). The name is for the type locality, Brumado, Bahia, Brazil. The new mineral species has been approved by the CNMNC (IMA 2008-028). (AU)

• Processo FAPESP: 05/53741-1 - Os novos minerais brasileiros: caracterização e descrição
• Beneficiário: Daniel Atencio
• Modalidade de apoio: Auxílio à Pesquisa - Regular