Selenite (Gypsum)CaSO4 - 2H2O
Class: Sulfate Hardness: 2 Density: 2.3 Streak: White Lustre: Vitreous Habit: Large crystalline habit Colours: Colourless, clear | | Crystal System: Monoclinic Cleavage: Perfect Fracture: Splintery Magnetism: None Reaction with HCl: Weak | Identification in hand sample: Single large crystals of gypsum, typified by hardness and transparency. Associations: Found in marine evaporites. Industrial / ecomonic uses: Used in gypsum wallboard. Comments: Sometimes called "satin spar". |