Hydrothermal anhydrite in veins is usually hydrated to gypsum by groundwater in close to-surface exposures. It is frequently connected to the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances uncovered as impurities may perhaps give an array of hues to local https://www.propanraya.com/id/produk/eco-gypsum-ee-4050