Augite
Chemical Formula	(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6
Species	Silicates
Crystal System	Monoclinic
Mohs Scale	5-6
Specific Gravity	3.19-3.56
Color	Black, brown, greenish, Purple-brown; in thin section, colorless to gray with zoning common
Streak	Greenish-white
Luster	Vitreous, Resinous, Dull
Refractive Index	n = 1.680 - 1.735 n = 1.684 - 1.741 n = 1.706 - 1.774
Diaphaneity	Translucent, Opaque
Cleavage	Distinct/GoodGood on
Fracture	Irregular/Uneven, Sub-Conchoidal
Crystal Habit：Commonly as stubby prismatic crystals, also acicular, skeletal, dendritic
Geological Setting：Major rock forming mineral in mafic igneous rocks, ultramafic rocks and some high grade metamorphic rocks.