Yttrocerite
Yttrocerite is a variety of the mineral fluorite with a chemical formula CaF2+F3. It is bluish red with Cubic [crystal system|isometric] crystals and is named for the yttrium and cerium it contains. It has a Mohs hardness of 4–5. It has been found in Sweden, several states in the United States and Norway. It is not a mineral species approved by International [Mineralogical Association].