Hydrothermal Anhydrite in veins is usually hydrated to gypsum by groundwater in close to-surface area exposures. It is commonly associated with the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances located as impurities may possibly give a variety of colors https://www.propanraya.com/id/produk/eco-gypsum-ee-4050