Hydrothermal Anhydrite in veins is usually hydrated to gypsum by groundwater in in the vicinity of-area exposures. It is usually associated with the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances found as impurities may well give a wide range https://www.propanraya.com/id/produk/eco-gypsum-ee-4050