Hydrothermal Anhydrite in veins is often hydrated to gypsum by groundwater in around-area exposures. It is frequently related to the minerals halite and sulfur. Gypsum is the most typical sulfate mineral.[17] Pure gypsum is white, but other substances found as impurities may well give a variety of colours to nearby https://www.propanraya.com/id/produk/eco-gypsum-ee-4050