Members of the Freibergite-Argentotennantite Series and Associated Minerals from Silvermines, County Tipperary, Ireland

Marek A. Zakrzewski
Institute of Earth Sciences, Free University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands

Abstract: Ore microscope and electron microprobe investigations on Zn-Pb-Ag ores from B Zone in Silvermines, Ireland, have shown the presence of two As-Sb-Ag phases; a tetrahedrite-group mineral with composition Cu6.3Ag3.7Fe0.9Zn1.2As2.2Sb2.1S12.7 and proustite-pyrargyrite (Ag3As0.5Sb0.5S3). It is postulated that both phases inherited their As and Sb from primary geocronite (Pb14.5As3.4Sb2.6S23) and that they are metastable. An enrichment in Ni in the ores is due to very fine to submicroscopic intergrowths of gersdorffite (Ni0.6Fe0.4AsS) with geocronite and with galena.

Keywords: freibergite • argentotennantite • tetrahedrite group • Silvermines • Ireland

Mineralogical Magazine; June 1989 v. 53; no. 371; p. 293-298; DOI: 10.1180/minmag.1989.053.371.03
© 1989, The Mineralogical Society
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