Naujakasite

General Information: Chemical Formula:Na6(Fe++,Mn)Al4Si8O26 Composition:(Molecular Weight = 942.15 gm)Sodium 14.64 % NaManganese 1.46 % MnAluminum 11.46 % AlIron 4.45 % FeSilicon 23.85 % SiOxygen 44.15 % O  Empirical Formula: Na6Fe2+0.75Mn2+0.25Al4Si8O26Physical Properties: Cleavage:[001] Perfect, [401] Distinct, [010] Distinct Color:gray, pearl white, or silver white. Density:2.622 Hardness:2-3 - Gypsum-Calcite Luster:Pearly Streak:gray whiteMore details...