Ernstite

General Information:
 Chemical Formula:
(Mn++1-xFe+++x)Al(PO4)(OH)2-xOx
 Composition:
(Molecular Weight = 210.86 gm)
Manganese 13.03 % Mn
Aluminum 12.80 % Al
Iron 13.24 % Fe
Phosphorus 14.69 % P 
Hydrogen 0.72 % H 
Oxygen 45.53 % O 
 Empirical Formula:
Mn2+0.5Fe3+0.5Al(PO4)(OH)1.5O0.5
 Environment:
Oxidation product of eosphoite in granitic pegmatite.
 IMA Status:
Approved IMA 1970
 Locality:
Daib-East farm, Karibib, Namibia.
 Name Origin:
Named for Theodor K. A. Ernst (1904-), mineralogist, University of Erlangen, Germany.
Physical Properties:
 Cleavage:
[010] Good, [100] Good
 Color:
yellow brown.
 Density:
3.07
 Diaphaniety:
Translucent
 Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Aggregates - Made of numerous individual crystals or clusters.,
 Hardness:
3-3.5 - Calcite-Copper Penny
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