Althausite

General Information:
 Chemical Formula:
Mg2(PO4)(OH,F,O)
 Composition:
(Molecular Weight = 161.09 gm)
Magnesium 30.18 % Mg
Phosphorus 19.23 % P 
Hydrogen 0.38 % H 
Oxygen 46.68 % O 
Fluorine 3.54 % F 
 Empirical Formula:
Mg2(PO4)(OH)0.6F0.3O0.1
 IMA Status:
Approved IMA 1974
Physical Properties:
 Cleavage:
[???] Perfect
 Color:
gray.
 Density:
2.97
 Diaphaniety:
Translucent
 Hardness:
3.5 - Copper Penny
 Luster:
Vitreous (Glassy)
 Streak:
white
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