General Information: Chemical Formula:(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6
Environment:Basic igneous and metamorphic rocks.
IMA Status:Approved IMA 1980
Locality:Common world wide.
Name Origin:From the Greek auge - "luster."
Physical Properties: Cleavage:[110] Perfect, [010] Indistinct
Color:brown green, green, light brown, dark brown, or black.
Density:3.2 - 3.6, Average = 3.4
Diaphaniety:Translucent to opaque
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
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