Vlasovite

General Information:
 Chemical Formula:
Na2ZrSi4O11
 Composition:
(Molecular Weight = 425.54 gm)
Sodium 10.81 % Na
Zirconium 21.44 % Zr
Silicon 26.40 % Si
Oxygen 41.36 % O 
 Empirical Formula:
Na2ZrSi4O11
 IMA Status:
Approved IMA 1961
Physical Properties:
 Cleavage:
[010] Distinct
 Color:
colorless.
 Density:
2.97
 Diaphaniety:
Transparent
 Hardness:
6 - Orthoclase
 Luminescence:
Fluorescent.
 Luster:
Vitreous - Greasy
 Streak:
white
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