Map Of gypsum deposits in northern Ohio, black squares suggest The placement of deposits, from "Geography of Ohio", 1923 Gypsum is used in a wide variety of applications: Impurities in refinery gypsum squander have, in many instances, prevented them from being used as ordinary gypsum in fields such as building. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050