Johannite

General Information: Chemical Formula:Cu(UO2)2(SO4)2(OH)2·8(H2O) Composition:(Molecular Weight = 973.87 gm)Uranium 48.88 % U Copper 6.53 % CuHydrogen 1.86 % H Sulfur 6.59 % S Oxygen 36.14 % O  Empirical Formula: Cu(UO2)2(SO4)2(OH)2·8(H2O)Physical Properties: Cleavage:[100] Good Color:yellow or greenish yellow. Density:3.3 - 3.5, Average = 3.4 Diaphaniety:Transparent to Translucent Habits:Druse - Crystal growth in a cavity which results in numerous crystal tipped surfaces., Reniform - "Kidney like" in shape (e.g.. hematite)., Massive - Uniformly indistinguishable cryst als forming large masses. Hardness:2 - Gypsum Luminescence:Non-fluorescent. Luster:Vitreous (Glassy) Streak:light greenMore details...