BUCKHORNITE, PB2AUBITE2S3, FROM THE JILOV E GOLD DEPOSIT, CZECH-REPUBLIC

Citation
Z. Johan et al., BUCKHORNITE, PB2AUBITE2S3, FROM THE JILOV E GOLD DEPOSIT, CZECH-REPUBLIC, Comptes rendus de l'Academie des sciences. Serie 2, Mecanique, physique, chimie, sciences de l'univers, sciences de la terre, 318(9), 1994, pp. 1225-1231
Citations number
10
Categorie Soggetti
Multidisciplinary Sciences
ISSN journal
07644450
Volume
318
Issue
9
Year of publication
1994
Part
2
Pages
1225 - 1231
Database
ISI
SICI code
0764-4450(1994)318:9<1225:BPFTJE>2.0.ZU;2-N
Abstract
Buckhornite, Pb2AuBiTe2S3, recently described as a new mineral (Franci s et al., 1993), occurs in the Jilove gold deposit, Czech Republic. It is associated with pyrite, nagyagite, tellurobismuthite, altaite, gal ena, calaverite and native gold. Microprobe analyses gave the empirica l formula Pb2.133Au1.033(Bi0.687Sb0.308)0.995Te2.048S2.952. Buckhornit e is orthorhombic, P m m m or P 2 2 2; a = 9.374(4), b = 12.326(4), c = 4.073(2) angstrom; V = 470.61 angstrom3, Z = 2; D(calc) = 8.347 g/cm 3. The electron diffraction study reveals a face-centred cubic sub-cel l with a/3, b/6, c/2, whose dimensions correspond to [002], [022] and [022BAR] of the PbS-PbTe solid solution unit-cell. Microprobe analyses of associated angyagite gave Pb5.05gAu0.980(Sb0.861Bi0.255)1.116Te2,0 70S5.930. Consequently, the ideal formula can be written Pb5Au(Sb,Bi)T e2S6. The association buckhornite + nagyagite makes it possible to est imate the solubility limits of Sb and Bi respectively in the crystal s tructures of these two mineral phases. These limits are close to 1/3 o f Bi sites occupied by Sb in the buckhornite structure and to 1/4 of S b sites occupied by Bi in the nagyagite structure.