Epididymite

General Information:
 Chemical Formula:
NaBeSi3O7(OH)
 Composition:
(Molecular Weight = 245.26 gm)
Sodium 9.37 % Na
Beryllium 3.67 % Be
Silicon 34.35 % Si
Hydrogen 0.41 % H 
Oxygen 52.19 % O 
 Empirical Formula:
NaBe(Si3O7)(OH)
 Locality:
Island of Aro, Langesundfiord, Norway.
Physical Properties:
 Cleavage:
[001] Perfect, [010] Perfect
 Color:
colorless, white, gray, yellow, or blue.
 Density:
2.55
 Diaphaniety:
Transparent to translucent
 Hardness:
5.5 - Knife Blade
 Luster:
Vitreous (Glassy)
 Streak:
white
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