Wiktionary
yttrocerite
n. (context mineralogy English) A violet-blue mineral, a hydrous fluoride of cerium, yttrium, and calcium.
Wikipedia
Yttrocerite
Yttrocerite is a variety of the mineral fluorite with a chemical formula Ca F+( Y, Ce) F. It is bluish red with 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.