Zirconolite (CaZrT¡2OJ is a rare accessory mineral, described in a wide range of rock types and geological environmehts.fhe chemical composition of zirconolite can vary extensively, with the main substitutions involving. REE, Nb,Y, U, Th y Fe. Zirconolite has been described from 46 terrestrial localities arid from 13 lunar samples, but it has not been reported in Spain. The zirconolite of Fuerteventura occurs in leucocratic vein frôm brécçiaied zone, at the contact aureola of the Pájára pluion. It occurs as rims surrounding, zircon arid is considered to have been formed by metasomatic substitution of zircon with addition C.a, ti,
Fe, REE, Nb, Ÿ, U y Th which were fràctionated into the fluid during its separation frorti the melt