Kukharenkoite-(Ce) mineral

A barium-cerium fluorocarbonate mineral with the ideal IMA-CNMNC September 2026 formula Ba2Ce(CO3)3F and approval identifier 1995-040. This record denotes the Ce-dominant mineral species, not kukharenkoite-(La), a carbonatite ore or its constituent elements. Zaitsev et al. (1996) described natural specimens from the Khibina and Vuorijarvi massifs in Russia and the Mont Saint-Hilaire and Saint-Amable massifs in Quebec. Their KH1 specimen has mean Ce2O3 of 15.30 wt% and La2O3 of 6.61 wt% across twelve microprobe analyses (Table 2); this is a mixed-rare-earth natural composition, not the ideal pure-Ce formula or a recovery measurement. CO2 was calculated from stoichiometry because insufficient material was available for direct determination. Small apparent La dominance in KH5 was explicitly considered inconclusive because of interference-correction uncertainty; it is not assigned to the La species here. Krivovichev et al. (1998) refined a natural KH1 crystal from manganoan ankerite carbonatite at 293(2) K in monoclinic P21/m, with R = 0.044 using 2296 observed reflections. The idealized Ba2Ce(CO3)3F structural model and fluorine-centered coordination describe that mixed-REE natural crystal; they do not constitute a mineral-formation or extraction experiment. The 1996 description reports solubility in hydrochloric acid with effervescence without specifying acid concentration, duration, temperature, solid loading or yield. No quantified leaching or isolated-product recovery is inferred. Its suggested equivalence to historical zhonghuacerite-(Ce) was tentative because original material was unavailable. Deposited observed and calculated structure factors cited by the 1998 paper were not acquired. No microbial mechanism, industrial deployment or dated criticality designation is asserted.

Record source: data/records/kukharenkoite-ce.yaml