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
More details...