Formula: (Ca_1-xY_x)F_2+x where 0.05< x Species:

Name: Named for chemical composition. A variety of Fluorite

First Recorded Locality: Hundholmen, Narvik, Nordland, Norway

Yttrofluorite is a variety of fluorite containing an appreciable amount of trivalent yttrium (Y) taking the place of divalent calcium (Ca) cations in the fluorite structure. Many early identifications of yttrofluorite are likely to be purple fluorite without appreciable yttrium. Yttrofluorite is not commonly purple.
Originally reported from Hundholmen, Tysfjord, Nordland, Norway. [Precise locality mentioned in Vogt 1923.]