Hydrothermal Anhydrite in veins is commonly hydrated to gypsum by groundwater in around-surface exposures. It is usually linked to the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[seventeen] Pure gypsum is white, but other substances observed as impurities may well give an array of shades to regional https://www.propanraya.com/id/produk/eco-gypsum-ee-4050