Okenite

(n.)
A massive and fibrous mineral of a whitish color, chiefly hydrous silicate of lime.
  

General Information:
 Chemical Formula:
Ca3[Si6O15]·6(H2O)
 Composition:
(Molecular Weight = 1,966.57 gm)
Calcium 20.38 % Ca
Silicon 25.71 % Si
Hydrogen 1.85 % H 
Oxygen 52.07 % O 
 Empirical Formula:
Ca10Si18O46·18(H2O)
 Environment:
Secondary mineral from the alteration of basalts.
 Locality:
Disko Island, Greenland. Poona, near Bombay, India.
 Name Origin:
Named after the German natural historian, Lorenz Oken (1779-1851), Munich Germany.
Physical Properties:
 Cleavage:
[001] Good
 Color:
white, yellowish white, or bluish white.
 Density:
2.3 - 2.33, Average = 2.31
 Diaphaniety:
Transparent to Translucent
 Habits:
Capillary - Very slender and long, like a thread or hair (e.g. millerite)., Spherical - Spherical, rounded aggregates., Fibrous - Crystals made up of fibers.
 Hardness:
5 - Apatite
 Luminescence:
Fluorescent.
 Luster:
Pearly
 Streak:
white
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