Calcination: The powdered gypsum is heated to remove h2o molecules, manufacturing unique varieties of plaster according to the temperature and period of heating. Map of gypsum deposits in northern Ohio, black squares reveal The placement of deposits, from "Geography of Ohio", 1923 Gypsum is Employed in lots of purposes: For https://www.propanraya.com/id/produk/eco-gypsum-ee-4050