Umbite

Umbite (K2(Zr,Ti)Si3O9·H2O) is a mineral found in northern Russia.
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General Information:
 Chemical Formula:
K2ZrSi3O9·(H2O)
 Composition:
(Molecular Weight = 689.36 gm)
Potassium 11.34 % K 
Zirconium 52.93 % Zr
Silicon 12.22 % Si
Hydrogen 0.29 % H 
Oxygen 23.21 % O 
 Empirical Formula:
K2Zr4Si3O9·(H2O)
Physical Properties:
 Cleavage:
[010] Perfect, [100] Good
 Color:
colorless or yellowish white.
 Density:
2.79
 Diaphaniety:
Transparent
 Hardness:
4.5 - Between Fluorite and Apatite
 Luster:
Vitreous (Glassy)
 Streak:
white
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