Arrojadite

General Information:
 Chemical Formula:
KNa4CaMn++4Fe++10Al(PO4)12(OH,F)2
 Composition:
(Molecular Weight = 2,151.01 gm)
Potassium 1.82 % K 
Sodium 4.28 % Na
Calcium 1.86 % Ca
Manganese 10.22 % Mn
Aluminum 1.25 % Al
Iron 25.96 % Fe
Phosphorus 17.28 % P 
Hydrogen 0.07 % H 
Oxygen 36.82 % O 
Fluorine 0.44 % F 
 Empirical Formula:
KNa4CaMn2+4Fe2+10Al(PO4)12(OH)1.5F0.5
 Environment:
Granitic pegmatites and phosphate rich marine sediments.
 Locality:
Nickel Plate mine in the Keystone district, South Dakota.
Physical Properties:
 Cleavage:
[001] Distinct
 Color:
olive green, clove brown, or yellow.
 Density:
3.56
 Diaphaniety:
Translucent
 Hardness:
5 - Apatite
 Luster:
Vitreous - Greasy
 Streak:
green gray
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