Hydrothermal Anhydrite in veins is commonly hydrated to gypsum by groundwater in in close proximity to-surface area exposures. It is frequently affiliated with the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[17] Pure gypsum is white, but other substances identified as impurities may possibly give a wide array https://www.propanraya.com/id/produk/eco-gypsum-ee-4050