Omphacite
Chemical Formula	(Ca,Na)(Mg,Fe2+,Al)Si2O6
Species	Silicates
Crystal System	Monoclinic
Mohs Scale	5-6
Specific Gravity	3.16-3.43
Color	Green to dark green; colorless to pale green in thin section
Streak	Greenish white
Luster	Vitreous to silky
Refractive Index	n = 1.662 - 1.701 n = 1.670 - 1.712 n = 1.685 - 1.723
Diaphaneity	Translucent
Cleavage	Distinct/Good
Fracture	Uneven to conchoidal
Crystal Habit：Rarely in rough crystals; anhedral, granular to massive