Maoniupingite-Ce: a new rare-earth mineral from the Maoniuping rare-earth deposit in Mianning, Sichuan

Maoniupingite-Ce approved by IMA CNMMN as a new rare-earth mineral and a new member of the chevkinite subgroup is identified in the veins of carbonatites, pegmatitic carbonatites and alkaline rocks from the Maoniuping rare-earth deposit in Mianning, Sichuan. Compared with the known equivalents, the new mineral is interpreted to be either the Fe³⁺ analogue of chevkinite-(Ce) at the B site or the Fe³⁺ analogue of polyakovite-(Ce) at the B and C sites, and directly crystallized from a type of F-, water- and REE-rich mineralizing fluids during the transitional stages of magmatic-hydrothermal processes.