Sadanagaite

General Information: Chemical Formula:(K,Na)Ca2(Fe++,Mg,Al,Ti)5[(Si,Al)8O22](OH)2 Composition:(Molecular Weight = 931.99 gm)Potassium 3.15 % K Sodium 0.62 % NaCalcium 8.60 % CaMagnesium 3.91 % MgTitanium 1.28 % TiAluminum 7.96 % AlIron 14.98 % FeSilicon 18.08 % SiHydrogen 0.22 % H Oxygen 41.20 % O  Empirical Formula: K0.75Na0.25Ca2Fe2+2.5Mg1.5Al0.75Ti0.25(Si6Al2O22)(OH)2 Environment:With lenses in titanian diopside (fassaite). IMA Status:Approved IMA Locality:Yuge Island, Fukui Prefecture, Japan. Name Origin:Named for Ryoichi Sadanaga (1920-), professor emeritus, University of Tokyo.Physical Properties: Cleavage:[110] Perfect Color:dark brown or black. Density:3.3 Diaphaniety:Transparent to Translucent Hardness:6 - Orthoclase Luster:Vitreous (Glassy) Streak:light brownMore details...