| Full text | |
| Author(s): |
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]
Total Authors: 10
|
| Affiliation: | [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
Total Affiliations: 6
|
| Document type: | Journal article |
| Source: | MINERALOGICAL MAGAZINE; v. 72, n. 6, p. 1201-1205, DEC 2008. |
| Web of Science Citations: | 2 |
| Abstract | |
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) | |