Barbertonite

General Information:
 Chemical Formula:
Mg6Cr2(CO3)(OH)16·4(H2O)
 Composition:
(Molecular Weight = 654.01 gm)
Magnesium 22.30 % Mg
Chromium 15.90 % Cr
Hydrogen 3.70 % H 
Carbon 1.84 % C 
Oxygen 56.27 % O 
 Empirical Formula:
Mg6Cr2(CO3)(OH)16·4(H2O)
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
violet, pink, or pink violet.
 Density:
2.1
 Diaphaniety:
Transparent to Translucent
 Hardness:
1.5-2 - Talc-Gypsum
 Luster:
Pearly
 Streak:
white
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