Labradorite
Chemical Formula	(Ca,Na)(Al,Si)4O8, where Ca/(Ca + Na) (% anorthite) is between 50%–70%
Species	Silicates
Crystal System	Triclinic
Mohs Scale	6
Specific Gravity	2.68-2.72
Color	Gray, brown, greenish, blue, yellow, colorless
Streak	white
Luster	Sub-Vitreous
Refractive Index	n = 1.554 - 1.563 n = 1.559 - 1.568 n = 1.562 - 1.573
Diaphaneity	Translucent to transparent
Cleavage	Perfect
Fracture	Uneven to conchoidal
Crystal Habit：Crystals typically thin and tabular, rhombic in cross section, striated; massive