Color is black to steel gray to silver. Luster is metallic. Transparency crystals are opaque. Twinning is occassionally seen. Also massive and granular.
Cleavage is absent.
Fracture is conchoidal. Streak is black to brown. Associated Minerals are quartz , pyrite , galena , chalcopyrite and other sulfides. Best Field Indicators are crystal habit, lack of cleavage and color.