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