Hydrothermal Anhydrite in veins is commonly hydrated to gypsum by groundwater in in the vicinity of-surface area exposures. It is frequently connected to the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances located as impurities may give a variety of hues https://www.propanraya.com/id/produk/eco-gypsum-ee-4050