Titre du document / Document title

Crystal structure refinement of a wallisite-hatchite solid solution

Auteur(s) / Author(s)

BOIOCCHI Massimo ; CALLEGARI Athos ;

Résumé / Abstract

X-ray single-crystal diffraction data of a wallisite-hatchite solid solution (from Binnatal, Switzerland) have been collected using a Bruker-Axs three-circle diffractometer equipped with the Smart-Apex CCD detector. The chemical formula of the studied crystal is: PbTl(Cu^0.64Ag^0.36)As²S⁵. It is triclinic, with a = 9.071(1), b = 7.787(1), c = 8.039(1), a = 65.83(1), β = 65.05(1), γ = 74.22(1), space group P 1, Z = 2. The original determinations of the crystal structure proposed by MARUMO & NOWACKI (1967) for hatchite and by TAKÉUCHI et al. (1968) for wallisite are substantially confirmed. Our structure refinement [which converges to Robs = 0.038 for 3054 observed reflections with I/σ(I) ≥ 3] allows a better description of the structural features and of the crystal-chemical behaviour along the hatchite-wallisite binary join. The mean atomic number refined at the tetrahedral (T) site agrees with the estimated chemical formula, whereas the partitioning of Pb and Tl between the two independent M site is proposed combining geometrical and bond valence considerations.

Revue / Journal Title

Neues Jahrbuch für Mineralogie Monatshefte   ISSN 0028-3649   CODEN NJMMAW 

Source / Source

2003, n^o9, pp. 396-406 [11 page(s) (article)]

Langue / Language

Anglais
Revue : Multilingue

Editeur / Publisher

Schweizerbart'sche, Stuttgart, ALLEMAGNE  (1950-2004) (Revue)

Localisation / Location

INIST-CNRS, Cote INIST : 924 A, 35400011239168.0020