Ceruleite

General Information: Chemical Formula:Cu2Al7(AsO4)4(OH)13·12(H2O) Composition:(Molecular Weight = 1,308.92 gm)Aluminum 14.43 % AlCopper 9.71 % CuArsenic 22.90 % AsHydrogen 2.85 % H Oxygen 50.12 % O  Empirical Formula: Cu2Al7AsO44(OH)13·12(H2O)Physical Properties: Color:blue or deep blue. Density:2.7 Hardness:5-6 - Between Apatite and Orthoclase Streak:bluish whiteMore details...

C 2Al7(AsO4)4(OH)13 12(H2O)