Hydrothermal anhydrite in veins is usually hydrated to gypsum by groundwater in in the vicinity of-floor exposures. It is often linked to the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances located as impurities could give a variety of colours to https://www.propanraya.com/id/produk/eco-gypsum-ee-4050