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
More details...