Kegelite

General Information:
 Chemical Formula:
Pb8Al4Si8O20(SO4)2(CO3)4(OH)8
 Composition:
(Molecular Weight = 2,878.42 gm)
Aluminum 3.75 % Al
Silicon 7.81 % Si
Hydrogen 0.28 % H 
Lead 57.59 % Pb
Carbon 1.67 % C 
Sulfur 2.23 % S 
Oxygen 26.68 % O 
 Empirical Formula:
Pb8Al4Si8(SO4)2(CO3)4(OH)8O20
 Environment:
Deep oxidation zone at the mine.
 IMA Status:
Approved IMA 1975
 Locality:
Tsumbe, Namibia.
 Name Origin:
Named for Friedrich Wilhelm Kegel, director of the Tsumbe mine from 1922 to 1938.
Physical Properties:
 Cleavage:
[???] Perfect
 Color:
colorless or pearl white.
 Density:
4.46 - 4.549, Average = 4.5
 Diaphaniety:
Transparent to Translucent
 Luster:
Pearly
 Streak:
white
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