REE minerals of fenites from the Čistá-Jesenice Pluton (Czech Republic)

The results of the study of mineral phases containing rare earth elements (REE) from the Čistá-Jesenice Pluton have been published in the Bulletin Mineralogie Petrologie. The research, carried out in cooperation with experts of the Department of Mineralogy and Petrology of the National Museum Prague, is a follow-up to the Czech Technology Agency project "Analysis of new occurrences of rare earth elements", which ended in June 2021.

Alkaline metasomatites originated from granitoids of the Čistá-Jesenice Pluton contain a rich association of REE-bearing minerals. Whereas occurrence of REE carbonates (bastnäsite, parisite), monazite, rhabdophane, churchite, fergusonite and pyrochlore was found in relatively weakly altered rocks, much richer assemblage was observed in rocks which underwent the strongest metasomatism (so called reomorphic cancrinite-nepheline syenites). Here, the mineral assemblage contains also xenotime and REE silicates, including tritomite/melanocerite, allanite, perbøeite, gadolinite and a Mn-analogue of hingganite. Cerium, yttrium, and to lesser extent also lanthanum are dominating cations in the studied REE phases. A total of 24 mineral species was identified, including three unnamed phases. The article is available online.