Jahnsite-(CaMnFe)

General Information:
 Chemical Formula:
CaMn++Fe++2Fe+++2(PO4)4(OH)2·8(H2O)
 Composition:
(Molecular Weight = 876.43 gm)
Calcium 4.57 % Ca
Manganese 6.27 % Mn
Iron 25.49 % Fe
Phosphorus 14.14 % P 
Hydrogen 2.07 % H 
Oxygen 47.46 % O 
 Empirical Formula:
CaMn2+Fe2+2Fe3+2(PO4)4(OH)2·8(H2O)
 IMA Status:
Approved IMA
 Locality:
Fletcher mine, North Groton, New Hampsire, USA.
 Name Origin:
Named for Richard H. Jahns (1915-1983), mineralogist and pegmatite expert, Stanford University, Palo Alto, California, USA.
Physical Properties:
 Cleavage:
[001] Good
 Color:
brown, purplish brown, yellow, or yellow orange.
 Density:
2.86
 Diaphaniety:
Transparent to Translucent
 Hardness:
4 - Fluorite
 Luster:
Vitreous - Adamantine
 Streak:
white
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