Bechererite

General Information: Chemical Formula:(Zn,Cu)6Zn2(OH)13[(S,Si)(O,OH)4]2 Composition:(Molecular Weight = 933.60 gm)Zinc 45.53 % ZnSilicon 1.50 % SiCopper 10.21 % CuHydrogen 1.62 % H Sulfur 5.15 % S Oxygen 35.99 % O  Empirical Formula: Zn4.5Cu1.5Zn2OH132(S0.75)2(Si0.25)2(O3)2(OH) Environment:Alteration product of copper and zinc orebodies. IMA Status:Approved IMA 1995 Locality:The dump of the Tonopah-Belmont mine, Osborne silver-gold district, Maricopa County, Arizona USA. Name Origin:Named after Dr. Karl Becherer (1926-) of the University of Vienna, in recognition of his contributions to the mineralogy of Spangolite from Lavrion.Physical Properties: Cleavage:[001] Perfect Color:light green. Density:3.45 - 3.49, Average = 3.47 Diaphaniety:Transparent Habits:Druse - Crystal growth in a cavity which results in numerous crystal tipped surfaces., Spherical - Spherical, rounded aggregates., Acicular - Occurs as needle-like crystals. Hardness:2.5-3 - Finger Nail-Calcite Luminescence:Non-fluorescent. Luster:Vitreous (Glassy) Streak:whiteMore details...