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