Vesuvianite
Jeffrey Pit
Asbestos, Quebec, Canada
This specimen measures 11cm x 8cm
Vesuvianite (Idocrase) Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4
Sorosilicates; basic calcium, magnesium, aluminum silicate, often with som beryllium and fluorine
Color and Luster: Brown, green, rarely yellow or blue; vitreous; greasy, resinous; streak white
Hardness: 6.5
Cleavage: Poor, one direction
Fracture: Uneven to conchoidal, brittle
Crystals: Tetragonal; usually in short prismatic crystals with square cross section; also columnar, granular, compact like jade
Photo by Mary Sutherland
Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals