EXAFS and Mössbauer Spectroscopic Study of Febearing Tetrahedrites

J. M. Charnock, C. D. Garner, R. A. D. Pattrick and D. J. Vaughan
Department of Chemistry, The University, Manchester M13 9PL
Department of Geology, The University, Manchester M13 9PL

Abstract: EXAFS and Mössbauer data on synthetic silver-rich tetrahedrite, (Cu, Ag)10+xFe2−xSb4S13, reveal the presence of Fe2+ and Fe3+ the former occupying trigonal planar sites and the latter tetrahedral sites. There is also a clear relationship between increased silver substitution and an increase in Fe2+. The amount of Fe3+ incorporated in the synthetic tetrahedrites is proportional to the excess of Cu+ (Cu + Ag > 10 atoms) in the mineral, thus maintaining a charge balance. The iron in the natural tetrahedrites and the tennantite examined is mainly tetrahedrally co-ordinated Fe2+.

Keywords: EXAFS • Mössbauer • Fe-bearing • tetrahedrites

Mineralogical Magazine; April 1989 v. 53; no. 370; p. 193-199; DOI: 10.1180/minmag.1989.053.370.06
© 1989, The Mineralogical Society
Mineralogical Society (www.minersoc.org)