Hydrothermal Anhydrite in veins is commonly hydrated to gypsum by groundwater in around-area exposures. It is commonly related to the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances discovered as impurities might give an array of colours to nearby deposits. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050