Wattevillite

General Information: Chemical Formula:Na2Ca(SO4)2·4(H2O) (?) Composition:(Molecular Weight = 350.25 gm)Sodium 13.13 % NaCalcium 11.44 % CaHydrogen 2.30 % H Sulfur 18.31 % S Oxygen 54.82 % O  Empirical Formula: Na2Ca(SO4)2·4(H2O) Environment:A questionable species. Associated with other sulfates in a pyritic lignite. Locality:Einigkeit mine, Bauersberg, near Bischofsheim, Bavaria, Germany. Name Origin:Named for Oscar de Watteville of Paris, France.Physical Properties: Color:white. Density:1.81 Habits:Microscopic Crystals - Crystals visible only with microscopes., Acicular - Occurs as needle-like crystals., Luster:Silky Streak:whiteMore details...