Nagashimalite

General Information: Chemical Formula:Ba4(V+++,Ti)4Si8B2O27Cl(O,OH)2 Composition:(Molecular Weight = 1,474.64 gm)Barium 37.25 % BaTitanium 3.25 % TiVanadium 10.36 % V Silicon 15.24 % SiHydrogen 0.03 % H Chlorine 2.40 % ClOxygen 31.46 % O  Empirical Formula: Ba4V3+3TiSi8O28.5Cl(OH)0.5 IMA Status:Approved IMA 1980Physical Properties: Cleavage:None Color:greenish black. Density:4.08 Hardness:6 - Orthoclase Luster:Sub Metallic Streak:greenMore details...