General Information:
Chemical Formula:
CaAl2Si2O7(OH)2·(H2O)
Composition:
(Molecular Weight = 314.24 gm)
Calcium 12.75 % Ca
Aluminum 17.17 % Al
Silicon 17.88 % Si
Hydrogen 1.28 % H
Oxygen 50.91 % O
Empirical Formula:
CaAl2Si2O7(OH)2·(H2O)
Environment:
Originally described from a crystalline schist associated with serpentine. Also found as a secondary mineral in altered gabbros and diorites.
Locality:
Reed Station, Tiburon peninsula, Marin County, California, USA.
Physical Properties:
Cleavage:
[010] Perfect, [001] Perfect, [110] Poor
Color:
colorless, white, gray, blue, or pinkish.
Density:
3.09
Diaphaniety:
Translucent to transparent
Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Tabular - Form dimensions are thin in one direction.,
Hardness:
7.5 - Garnet
Luminescence:
None.
Luster:
Vitreous - Greasy
Streak:
white
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