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