Hydrothermal anhydrite in veins is usually hydrated to gypsum by groundwater in in close proximity to-surface exposures. It is commonly affiliated with the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[17] Pure gypsum is white, but other substances discovered as impurities may well give a wide range of https://www.propanraya.com/id/produk/eco-gypsum-ee-4050