Tags: Chemical Substance, Mineral.
Freibergite is a complex sulfosalt mineral of silver copper iron antimony and arsenic with formula (AgCuFe)12(SbAs)4S13. It has cubic crystals and is formed in hydrothermal deposits. It forms one solid solution series with tetrahedrite and another with argentotennantite. Freibergite is an opaque metallic steel grey to black and leaves a reddish black streak. It has a Mohs hardness of 3.5 to 4.0 and a specific gravity of 4.85 – 5.
