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