Map Of gypsum deposits in northern Ohio, black squares point out the location of deposits, from "Geography of Ohio", 1923 Gypsum is Employed in numerous types of apps: Impurities in refinery gypsum waste have, in many scenarios, prevented them from being used as usual gypsum in fields for example construction. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050