Labradorite

(Ca,Na)(Si,Al)4O8

Cleavage: [001] Perfect, [010] Good, [110] Distinct
Color: Colorless, Gray, Gray white, White, Light green.
Density: 2.68 - 2.71, Average = 2.69
Diaphaniety: Translucent to transparent
Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habits: Granular - Generally occurs as anhedral to subhedral crystals in matrix.,
Crystalline - Coarse - Occurs as well-formed coarse sized crystals.,
Striated - Parallel lines on crystal sur face or cleavage face.
Hardness: 7 - Quartz
Luminescence: Non-fluorescent.
Luster: Vitreous (Glassy)
Streak: white