Color is black to steel gray. Luster is metallic. Transparency crystals are opaque. Twinning is occassionally seen. Also massive and granular.
Cleavage is absent.
Fracture is subconchoidal. Hardness is 3 - 4. Streak is black to reddish if rubbed. Associated Minerals are quartz , pyrite , arsenopyrite , chalcopyrite and other sulfides. Best Field Indicators are crystal habit, lack of cleavage, streak and color.