Fluorspar is also identified by the mineral name fluorite. Fluorspar (fluorite) is calcium fluoride. It originates in a variety of geologic surroundings. Fluorspar is found in granite (igneous rock), it fills cracks and holes in sandstone, and it is found in large deposits of limestone (sedimentary rock). The term fluorspar, when used as a product name, also refers to calcium fluoride formed as a by-product of industrial processes.