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