Gypsum is found in sedimentary rock formations across the world in over 85 countries and mined in 17 states. Gypsum is also known as calcium sulfate dihydrate.
Gypsum is mined in the United States most abundantly in Texas, Utah, Iowa and New Mexico. There is both natural gypsum and FGD gypsum. Natural gypsum is found in nature, while FGD gypsum is a byproduct of flue gas desulfurization. Some FGD gypsum can contain radon, which is harmful to humans. Natural gypsum is non-toxic and is mainly used for construction and building plasters. It is made up of sulfur bound to oxygen, water, and calcium.