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