Ferripyrophyllite

General Information:
 Chemical Formula:
Fe+++2Si4O10(OH)2
 Composition:
(Molecular Weight = 418.04 gm)
Iron 26.72 % Fe
Silicon 26.87 % Si
Hydrogen 0.48 % H 
Oxygen 45.93 % O 
 Empirical Formula:
Fe3+2Si4(OH)2O10
 IMA Status:
Approved IMA 1979
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
brownish yellow.
 Density:
2.6 - 3, Average = 2.8
 Diaphaniety:
Transparent to Translucent
 Hardness:
1-2 - Between Talc and Gypsum
 Luster:
Pearly
 Streak:
light yellow
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