Two other silver sulfosalts. Polybasite is difficult to distinguish from the minerals hematite , an oxide , and another silver antimony sulfide, stephanite . Hematite forms metallic steel gray platy crystals but has a blood-red streak and is considerably harder. Luster is metallic. Crystals are opaque to translucent in thin slices or at crystal edges.
Fracture is uneven.
Streak is a black to reddish-black. Associated Minerals include silver , quartz , galena , proustite , pyrargyrite , stephanite , tetrahedrite , acanthite and other silver sulfide minerals. Best Field Indicators are crystal habit, density, softness, cleavage, association with other silver sulfosalts and color.