Classification Of Gypsum

Generally, the so-called gypsum can generally refer to two minerals, raw gypsum and anhydrite. Gypsum is calcium sulfate dihydrate (Ca[SO4]·2H2O), also known as dihydrate gypsum, water gypsum or soft gypsum. The theoretical composition is CaO32.6%, SO346.5%, H2O+20.9%, monoclinic, crystal Plate-like, usually dense block or fibrous, white or gray, red, brown, glass or silk luster, Mohs hardness of 2, cleavage parallel {010} complete, density 2.3g/cm3; anhydrite is Anhydrous calcium sulfate (Ca[SO4]), theoretical composition CaO41.2%, SO358.8%, orthorhombic, the crystal is plate-like, usually dense block or granular, white, gray-white, vitreous, Mohs The hardness is 3-3.5, the cleavage is completely parallel to {010}, and the density is 2.8-3.0g/cm3. The two kinds of gypsum are often produced together, and can be transformed into each other under certain geological effects.