Calcioandyrobertsite

General Information:
 Chemical Formula:
KCaCu5(AsO4)4[As(OH)2O2]-2(H2O)
 Composition:
(Molecular Weight = 1,129.55 gm)
Potassium 3.46 % K 
Calcium 3.55 % Ca
Copper 28.13 % Cu
Arsenic 33.16 % As
Hydrogen 0.54 % H 
Oxygen 31.16 % O 
 Empirical Formula:
KCaCu5(AsO4)4(As(OH)2O2)·2(H2O)
 Environment:
Single specimen found at the mine. Forms a series with andyrobertsite.
 IMA Status:
Approved IMA (Dana # Added)
 Locality:
Tsumeb Mine, Tsumeb, Namibia.
 Name Origin:
Named after Andrew C. Roberts (1950-), mineralogist with the Geological Survey of Canada.
Physical Properties:
 Cleavage:
[100] Good
 Color:
electric blue.
 Density:
4.011
 Diaphaniety:
Transparent
 Habits:
Platy - Sheet forms (e.g. micas)., ,
 Hardness:
3 - Calcite
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
pale blue
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