Hydrothermal Anhydrite in veins is often hydrated to gypsum by groundwater in near-surface area exposures. It is frequently 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 may perhaps give a variety of hues to https://www.propanraya.com/id/produk/eco-gypsum-ee-4050