Fluorite (fluorspar) mining got its start in Illinois in 1842. The mineral is usually referred to as fluorite, while the product that is mined is called fluorspar. It was used as a flux to help remove impurities while smelting metals like iron and aluminum. It also is used in products ranging from optical lenses to fluoride (derived from fluorite) in toothpaste. Fluorspar production peaked in the 1960s when an average of 118,820 tons was mined annually. Fluorspar mining eventually became unprofitable due to competition from overseas producers, coupled with the high costs of underground mining. The last mine in Illinois closed in 1995. Fluorspar is no longer mined in the United States.