Hydrothermal Anhydrite in veins is commonly hydrated to gypsum by groundwater in in the vicinity of-area 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 uncovered as impurities might give a wide range of shades https://www.propanraya.com/id/produk/eco-gypsum-ee-4050