Calcium fluoride, or CaF2, is a chemical compound made up of calcium and fluorine. It appears as a colorless or white crystalline solid and is commonly found in nature as the mineral fluorite. CaF2 is used in various applications, including optics, where it serves as a lens material due to its low refractive index and high transmission of ultraviolet light. In addition to its optical uses, CaF2 is important in the production of aluminum and in the manufacture of certain types of glass. It also plays a role in the dental industry, where it is used in some toothpaste formulations to help prevent cavities.