General Information:
Chemical Formula:
(Ca,K,Ba)2V8O20·3(H2O)
Composition:
(Molecular Weight = 880.68 gm)
Potassium 2.22 % K
Barium 3.12 % Ba
Calcium 5.92 % Ca
Vanadium 46.27 % V
Hydrogen 0.69 % H
Oxygen 41.78 % O
Empirical Formula:
Ca1.3K0.5Ba0.2V4+8O20·3(H2O)
IMA Status:
Approved IMA 1983
Locality:
Union Carbide mine, Wilson Springs, Arkansas.
Name Origin:
Named for John A. Straczed (1914-), U. S. Geologist.
Physical Properties:
Cleavage:
[100] Perfect
Color:
greenish black.
Density:
3.19 - 3.21, Average = 3.2
Habits:
Microscopic Crystals - Crystals visible only with microscopes., Fibrous - Crystals made up of fibers.,
Hardness:
1-2 - Between Talc and Gypsum
Luster:
Greasy (Oily)
Streak:
greenish black
More details...