The identity of zinckenite and keeleyite

Abstract

Zinckenite was first described in 1826 by G. Rose, who determined it to be an orthorhombic mineral. The crystals were thought to be seldom single, but to occur in nearly hexagonal forms as a result of twinning in some fashion similar to that found in aragonite. The presence of longitudinal striations on the lateral faces was taken as further evidence that the crystals were twinned. The composition was given by H. Rose as PbSb2S4or PbS.Sb2S3. The original specimens which were described came from the antimony mine of Woffsberg in the Harz.In 1922 S. G. Gordon described a new lead sulfantimonite from Oruro, Bolivia, which he named keeleyite. This mineral he presumed to he orthorhombic, although no measurable crystals were found, and the formula was given as Pb2Sb6S11or 2PbS.3Sb2S3.