Color: usually black, can be green or greenish brown
Streak: white
Hardness: 5–6
Specific Gravity: 3.28–3.41
Cleavage: perfect (rhombic)
Fracture: uneven
Luster: silky to glassy
Crystal form: monoclinic
Transparency: transparent to opaque
Forms in igneous and metamorphic rocks.
For an explanation of the properties (in bold face), click here >>