Map Of gypsum deposits in northern Ohio, black squares reveal The situation of deposits, from "Geography of Ohio", 1923 Gypsum is Utilized in a wide variety of purposes: Impurities in refinery gypsum waste have, in lots of conditions, prevented them from getting used as normal gypsum in fields for example https://www.propanraya.com/id/produk/eco-gypsum-ee-4050