Genthelvite

General Information:
 Chemical Formula:
Zn4Be3(SiO4)3S
 Composition:
(Molecular Weight = 596.91 gm)
Beryllium 4.53 % Be
Zinc 43.82 % Zn
Silicon 14.12 % Si
Sulfur 5.37 % S 
Oxygen 32.16 % O 
 Empirical Formula:
Zn4Be3(SiO4)3S
Physical Properties:
 Cleavage:
None
 Color:
blue green, brown, colorless, green, or yellow.
 Density:
3.62
 Diaphaniety:
Transparent
 Hardness:
6-6.5 - Orthoclase-Pyrite
 Luminescence:
Phosphorescent fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
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