Orthoericssonite

General Information:
 Chemical Formula:
BaMn2(Fe+++O)Si2O7(OH)
 Composition:
(Molecular Weight = 504.22 gm)
Barium 27.24 % Ba
Manganese 21.79 % Mn
Iron 11.08 % Fe
Silicon 11.14 % Si
Hydrogen 0.20 % H 
Oxygen 28.56 % O 
 Empirical Formula:
BaMn2+2Fe3+Si2O8(OH)
 IMA Status:
Approved IMA 1970
Physical Properties:
 Cleavage:
[100] Perfect, [011] Distinct
 Color:
reddish black.
 Density:
4.21
 Hardness:
4.5 - Between Fluorite and Apatite
 Streak:
brown
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