Contribution
The crystal structure of jankovićite, Tl5Sb9(As,Sb)4S22
Libowitzky, Eugen; Giester, Gerald; Tillmanns, Ekkehart
European Journal of Mineralogy Volume 7 Number 3 (1995), p. 479 - 488
25 références bibliographiques
publié: May 18, 1995
manuscrit accepté: Nov 22, 1994
manuscrit reçu: May 2, 1994
DOI: 10.1127/ejm/7/3/0479
Abstract
Abstract The recently discovered mineral jankovićite with the formula Tl5Sb9(As,Sb)4S22 from the Allchar region, Macedonia, was investigated by single crystal X-ray diffraction methods. The structure was determined by direct methods from 3502 reflections, measured on a four-circle diffractometer, and refined to a final /lvalue of R/Rw = 0.062/0.038. The cell parameters are a0 = 7.393(4) Å, bo = 8.711(5) Å, c0 = 17.58(1) Å, α = 103.81(3)°, ß = 91.81(3)°, γ= 109.51(3)°; space group Pi, Z= 1. The structure consists of kinked chains of SbSn (n = 3, 2 + 2, 3 + 1, 3 + 2, 3 + 3) polyhedra //c which are connected by AsSn pyramids to form puckered layers // (100). These Sb-As-S layers are interconnected via Tl atoms in eight coordination. One Tl atom and one Sb atom share an approximately common site which is statistically occupied. The As sites are partially substituted by Sb. The structure shows close similarities with that of rebulite, Tl5Sb5As8S22.
Mots-clefs
jankovicite • Tl-sulfosalts • Allchar • Macedonia • crystal structure.