Semseyite

Although Semseyite is a lead-antimony sulphide, it is classified as a sulphosalt due to it containing both a metal (lead) and a semimetal (antimony) together with sulphur.  This cabinet specimen is a magnificent example of the species and the material from the Herja mine at Chiuzbaia in Romania is probably the world’s best.  This 9.4 x 7.5 cm plate has its top surface entirely encrusted with Semseyite, occurring as a hillocky substrate with a fine granular texture from which dozens of clusters of tabular Semseyite crystals emerge, giving the surface a spiky appearance with a sharp, hackly texture.  In a different way, the underside of the specimen is quite spectacular also, as the matrix is that of broad Semseyite convex plates of up to 8 cm diameter, with a thin veneer of a brassy gold mineral, most probably Pyrrhotite, but possibly Chalcopyrite.  A quite amazing specimen of this rare sulphosalt from the Herja mine and ex. the Dr Josef Clemente (1899-1987) Collection of southern Germany.