Edenite

General Information: Chemical Formula:NaCa2Mg5Si7AlO22(OH)2 Composition:(Molecular Weight = 834.25 gm)Sodium 2.76 % NaCalcium 9.61 % CaMagnesium 14.57 % MgAluminum 3.23 % AlSilicon 23.57 % SiHydrogen 0.24 % H Oxygen 46.03 % O  Empirical Formula: NaCa2Mg5Si7AlO22(OH)2 IMA Status:Approved IMA 1978Physical Properties: Cleavage:[110] Perfect, [010] Distinct Color:bluish green, colorless, gray, white, or light green. Density:3 - 3.059, Average = 3.02 Diaphaniety:Transparent to translucent Habits:Tabular - Form dimensions are thin in one direction., , Hardness:6 - Orthoclase Luminescence:Fluorescent. Luster:Vitreous (Glassy) Streak:whiteMore details...

NaCa2(Mg,Fe)5Si7AlO22(OH)2