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