Rhodizite

General Information:
 Chemical Formula:
(K,Cs)Al4Be4(B,Be)12O28
 Composition:
(Molecular Weight = 778.83 gm)
Cesium 4.27 % Cs
Potassium 3.77 % K 
Beryllium 8.10 % Be
Aluminum 13.86 % Al
Boron 12.49 % B 
Oxygen 57.52 % O 
 Empirical Formula:
K0.75Cs0.25Al4Be412(B0.75)12(Be0.25)O28
 IMA Status:
Approved IMA 1965
Physical Properties:
 Cleavage:
[???] Indistinct
 Color:
colorless, grayish, yellow, yellowish white, or white.
 Density:
3.44
 Diaphaniety:
Transparent to Translucent
 Hardness:
8.5 - Chrysoberyl
 Luster:
Vitreous - Adamantine
 Streak:
white
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