Davyne

General Information: Chemical Formula:Na4K2Ca2Si6Al6O24(SO4)Cl2 Composition:(Molecular Weight = 1,131.67 gm)Potassium 6.91 % K Sodium 8.13 % NaCalcium 7.08 % CaAluminum 14.31 % AlSilicon 14.89 % SiSulfur 2.83 % S Chlorine 6.27 % ClOxygen 39.59 % O  Empirical Formula: Na4K2Ca2Si6Al6O24(SO4)Cl2 IMA Status:Accepted IMA 1973 Locality:Mte. Somma, Vesuvius, Italy.Physical Properties: Cleavage:[1010] Perfect, [0001] Indistinct Color:colorless or white. Density:2.42 - 2.53, Average = 2.47 Diaphaniety:Transparent Hardness:6 - Orthoclase Luster:Vitreous (Glassy) Streak:whiteMore details...

(Na,Ca,K)8Al6Si6O24(Cl,SO4,CO3)2-3