Hydrothermal Anhydrite in veins is often hydrated to gypsum by groundwater in close to-surface area exposures. It is commonly linked to the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances discovered as impurities might give a variety of colours to community https://www.propanraya.com/id/produk/eco-gypsum-ee-4050