Jahnsite-(CaMnMn)

General Information:
 Chemical Formula:
CaMn++Mn++2Fe+++2(PO4)4(OH)2·8(H2O)
 Composition:
(Molecular Weight = 874.61 gm)
Calcium 4.58 % Ca
Manganese 18.84 % Mn
Iron 12.77 % Fe
Phosphorus 14.17 % P 
Hydrogen 2.07 % H 
Oxygen 47.56 % O 
 Empirical Formula:
CaMn2+Mn2+2Fe3+2(PO4)4(OH)2·8(H2O)
 IMA Status:
Approved IMA
 Locality:
Mangualde pegmatite, Beira, Portugal.
 Name Origin:
Named for Richard H. Jahns (1915-1983), mineralogist and pegmatite expert, Stanford University, Palo Alto, California, USA.
Physical Properties:
 Cleavage:
None
 Color:
brownish yellow.
 Density:
2.78
 Diaphaniety:
Transparent
 Hardness:
4 - Fluorite
 Luster:
Vitreous (Glassy)
 Streak:
white
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