Mantle composition, age and geotherm beneath the Darby kimberlite field, west central Rae Craton

Heamanite-(Ce), (K0.5Ce0.5)TiO3, a new perovskite supergroup mineral found in diamond from Gahcho Kué, Canada

“…Discoveries of exotic K and Na-rich metasomatic phases have also been increasing in mantlederived mantle xenoliths. For instance, priderite, freudenbergite and jeppeite have been observed in a range of metasomatized mantle material (e.g., Haggerty et al 1994;Giuliani et al 2012), while the Na-rich analogue of jeppeite, nixonite, was recently discovered (Anzolini et al 2019), also co-existing with priderite and freudenbergite, in a reaction rim around rutile (Harris et al 2018). This reaction relationship with rutile raises the possibility that the heamanite-(Ce) may have formed due to a reaction between a pre-existing rutile grain (several are present in the same diamond) and a K-Ce enriched metasomatic fluid similar to that which may have resulted in the formation of the goldschmidtite reported by Meyer et al (2019).…”