Hydrothermal Anhydrite in veins is often hydrated to gypsum by groundwater in around-surface exposures. It is commonly connected to the minerals halite and sulfur. Gypsum is the commonest sulfate mineral.[seventeen] Pure gypsum is white, but other substances found as impurities may possibly give an array of shades to neighborhood deposits. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050