Hydrothermal Anhydrite in veins is usually hydrated to gypsum by groundwater in in the vicinity of-floor exposures. It is frequently affiliated with the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances observed as impurities might give an array of shades https://www.propanraya.com/id/produk/eco-gypsum-ee-4050