General Information:
Chemical Formula:
Al2SiO5 = Al[6]Al[6]OSiO4
Composition:
(Molecular Weight = 162.05 gm)
Aluminum 33.30 % Al
Silicon 17.33 % Si
Oxygen 49.37 % O
Empirical Formula:
Al2SiO5
Environment:
Metamorphosed peri-aluminous sedimentary rocks.
IMA Status:
Approved IMA 1960
Locality:
Common world wide.
Name Origin:
From the Greek kyanos = "blue."
Physical Properties:
Cleavage:
[100] Perfect, [010] Imperfect
Color:
blue, white, gray, green, or black.
Density:
3.56 - 3.67, Average = 3.61
Diaphaniety:
Translucent to transparent
Habits:
Columnar - Forms columns, Fibrous - Crystals made up of fibers.,
Hardness:
4-7
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Pearly
Streak:
white
More details...