Hydrothermal anhydrite in veins is often hydrated to gypsum by groundwater in near-surface area exposures. It is usually connected with the minerals halite and sulfur. Gypsum is the most common sulfate mineral.[17] Pure gypsum is white, but other substances discovered as impurities might give a variety of colors to neighborhood https://www.propanraya.com/id/produk/eco-gypsum-ee-4050