Fluorite (CaF), also called fluorspar, is the main source of commercial fluorine. Fluorite is a colorful mineral associated with hydrothermal deposits. It is common and found worldwide. China supplies more than half of the world's demand and Mexico is the second-largest producer in the world.
The United States produced most of the world's fluorite in the early 20th century, but its last mine, in Illinois, shut down in 1995.  Canada also exited production in the 1990s. The United Kingdom has declining fluorite mining and has been a net importer since the 1980s.