Augite

(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6

Cleavage: [110] Perfect, [010] Indistinct
Color: Brown green, Green, Light brown, Dark brown, Black.
Density: 3.2 - 3.6, Average = 3.4
Diaphaniety: Translucent to opaque
Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habits: Massive - Fibrous - Distinctly fibrous fine-grained forms.,
Columnar - Forms columns,
Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Hardness: 5-6.5
Luminescence: Non-fluorescent.
Luster: Vitreous - Resinous
Streak: greenish gray