Recently, the International Mineralogical Association’s Commission on New Minerals, Nomenclature and Classification (IMA-CNMNC) unanimously approved a new mineral, “Huanghoite-(Nd),” discovered and submitted by a joint research team from China University of Geosciences and the Inner Mongolia Autonomous Region Geological Survey Institute, with the approval number IMA No. 2025-014. The discovery of Huanghoite-(Nd) is one of the innovative outcomes of the comprehensive budget project of the Inner Mongolia Autonomous Region Natural Resources Department, titled “Study on the Distribution Patterns and Occurrence Regularities of Rare Earth Elements in the Bayan Obo Deposit.” The research team, in collaboration with researchers from Jiangxi University of Applied Science and the Beijing Research Institute of Uranium Geology, named and submitted the mineral for approval.
Huanghoite-(Nd) typically occurs as anhedral crystals around 100 microns in size, with an ideal chemical formula of BaNd(CO3)2F, belonging to the trigonal crystal system with the space group R-3m. It is the neodymium-rich end-member of the Huanghoite mineral series and part of the rare earth carbonate mineral family. Its chemical composition and crystal structure were confirmed using modern analytical techniques such as electron probe microanalysis and X-ray diffraction, demonstrating a unique neodymium enrichment characteristic. Huanghoite-(Nd) was discovered in the central part of the main ore body of the Bayan Obo deposit in Inner Mongolia. The Bayan Obo deposit, the world’s largest rare earth deposit and a treasure trove of China’s mineral resources, has previously identified over 210 mineral species, with the proportion of new minerals steadily increasing. The approval of Huanghoite-(Nd) further highlights the complexity and resource diversity of this deposit.
During the project, the research team conducted systematic field geological surveys and geochemical analyses, revealing the distribution patterns and occurrence regularities of rare earth elements in the Bayan Obo deposit. Based on these findings, they established the zoning characteristics of the deposit’s ore bodies and a genetic model for the deposit. This model elucidated the mechanisms of selective enrichment of rare earth elements and iron during the differentiation and evolution of carbonatite magma. Guided by this genetic model, the research team discovered three new rare earth minerals in Bayan Obo through mineral micro-area analysis: Nd-fluorocarbonate, Nd-monazite, and Huanghoite-(Nd). Among these, Huanghoite-(Nd) received unanimous approval from the IMA-CNMNC, becoming the 25th new mineral identified in the Bayan Obo deposit.
The discovery and approval of Huanghoite-(Nd), along with the identification of neodymium-rich rare earth minerals in the Bayan Obo deposit, represent outcomes of theoretical guidance leading to new mineral discoveries following the establishment of the deposit’s genetic model. These research achievements not only enrich the theoretical system of rare earth mineralogy but also provide new pathways for the independent development and utilization of neodymium resources. Neodymium, a core component of high-performance permanent magnets (such as neodymium-iron-boron magnets), is in high demand in industries such as new energy vehicles, wind power generation, and electronic information. The discovery of neodymium-rich rare earth minerals is significant for understanding the occurrence states and substitution mechanisms of rare earth elements in the Bayan Obo deposit. This achievement marks a new milestone in researchers’ understanding of the occurrence regularities of rare earth elements in the Bayan Obo deposit, providing critical scientific support for the efficient development and comprehensive utilization of rare earth resources.
Source: China University of Geosciences
