Two new occurrences of benleonardite, a rare silver-tellurium sulphosalt, and a possible new occurrence of cervelleite

Abstract

AbstractBenleonardite, ideally Ag8(Sb,As)Te253, occurs in ore specimens from the Mayflower and Gies epithermal gold-silver telluride deposits in Montana commonly spatially associated with hessite and tetrahedrite. In these deposits, it is Cu-bearing (up to 2.7 wt.%) and exhibits a slight deficiency in Ag+Cu coupled with a slight excess in S. A cervelleite-like mineral coexists with benleonardite at Mayflower and is unusual in composition in that it is Se-bearing suggesting the possibility of solid solution with aguilarite (Ag4SeS).