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