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