Gypsum can be a tender sulfate mineral made up of calcium sulfate dihydrate, with the chemical system CaSO4·2H2O.[four] It is commonly mined and is made use of to be a fertilizer and as the major constituent in several forms of plaster, drywall and blackboard or sidewalk chalk. About geological time https://www.propanraya.com/id/produk/eco-gypsum-ee-4050