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