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