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Roger Weller, geology instructor
Chemical Group: silicate-pyroxene
Chemical Formula: CaMgSi2O6 with (Mg,Fe)(Al,Fe)2SiO6
Color: dark green to black
Luster: vitreous Transparency: translucent only on thin edges
Hardness: 5 to 6
Specific Gravity: 3.2 to 3.4
Cleavage: good prismatic cleavage (110)
Crystal Forms: Monoclinic
Crystals are usually prismatic. In cross section crystals are nearly square.
Mineral Associations: Augite is found commonly in dark-colored igneous rocks.
Augite is associated with plagioclase feldspars, nepheline, olivine, leucite, hornblende, magnetite.
Identifying Characteristics: darker color than diopside
Occurrences: Vesuvius in Italy, Bohemia
Toxicity: when-swallowed- low when inhaled- moderate