General Information:
Chemical Formula:(Co,Mg)(H3O)2[(UO2)SiO4]2·3(H2O)
Composition:(Molecular Weight = 835.75 gm)Magnesium 0.29 %
MgUranium 56.96 %
U Cobalt 6.35 %
CoSilicon 6.72 %
SiHydrogen 0.96 %
H Oxygen 28.72 %
O Empirical Formula: Co0.9Mg0.1(H3O)2(UO2)2(SiO4)2·(H2O)
Environment:In the oxidation zones of uranium ores.
IMA Status:Approved IMA 1982
Locality:Shikolobwe, Shava, Zaire.
Name Origin:Named from the French "oursin", sea urchin, in allusion to the radiating habit of the acicular crystals.
Physical Properties: Cleavage:[???] Good
Color:pale yellow.
Density:3.674
Diaphaniety:Transparent to Translucent
Habits:Acicular - Occurs as needle-like crystals., Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Aggregates - Made of numerous individual crystals or clusters.
Hardness:3-3.5 - Calcite-Copper Penny
Luster:Vitreous (Glassy)
More details...
