Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in around-floor exposures. It is usually connected with the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances uncovered as impurities may give an array of colours to regional deposits. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050