Freieslebenite
From Wikipedia, the free encyclopedia
Freieslebenite is a rare sulfide mineral of antimony, lead and silver with formula AgPbSbS3 and molecular weight of 533.02 g/mol. It is an opaque non-fluorescent mineral which has a hydrothermal origin. It is metallic, with a specific gravity of 6.3 and a Mohs hardness of 2.5 - about that of a finger nail. It is non-magnetic and is usually gray in colour. It has indistinct cleavage, and is brittle and has a conchoidal fracture. It can have a white or gray streak. It crystallizes in the monoclinic system.
[edit] History
Freieslebenite is normally found in Europe, usually in Romania and Germany. It was discovered in 1845, and is named after Johann Karl Freiesleben (1774 - 1846), Mining Commissioner of Saxony, Germany.
