Zirconolite, CaZrTi2O7, re-examined from its type locality at Afrikanda, Kola Peninsula, Russia and some Synroc implications
Bulakh, Andrei G.; Nesterov, Alexander R.; Williams, C. Terry
published: Apr 21, 2006
ArtNo. ESP154018202001, Price: 29.00 €
Zirconolite of Borodin et al. (1956) from type locality at Afrikanda, Kola Peninsula, Russia, consists of a core of calzirtite and baddeleyite, and a rim composed of an initial CaZrTi2O7 phase and various secondary minerals. This initial phase is both sector zoned and oscillatory zoned, and has variable composition. The principal substitutions are as follows: REE + Ti ⇔ Ca + Me5+; Me6+ + Me2+ ⇔ 2Ti; ACT4+ + Me2+ ⇔ Ca + Ti. Alteration of the initial phase is characterised by introduction of Si, H2O, Ba, Th and U, loss of Ca, Fe, Ti and Zr, and little change in Nb and REE. Zirconolite is an important constituent of Synroc, and it could easily be replaced by Si-bearing phases that concentrate U and Th much more then in initial ceramic material.