What is Xianhuaite-(Ce)?
Xianhuaite-(Ce) is a newly recognised cerium niobium oxide from the Bayan Obo deposit, with a rare tetragonal tungsten-bronze-type framework.
Mineralogy and structure
Reference formula: K2CeNb5O15. Xianhuaite-(Ce) is tetragonal with the ideal formula K2CeNb5O15 and a tungsten-bronze-type framework. Its 2024-approved species description is recent; no matching public COD CIF was selected for this batch. Xianhuaite-(Ce) is classified with oxides and has tetragonal crystal symmetry. Typical hardness is 5–6 on the Mohs scale and specific gravity is approximately 5.1–5.3.
Colour, lustre and habit
Typical colours include brownish red, pale yellow-brown, dark brown. The usual prismatic, granular, massive habit and adamantine, vitreous lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Xianhuaite-(Ce) forms in or is associated with rare-earth and niobium-rich alteration zones associated with the Bayan Obo ore deposit. Important documented localities include the East Mine of the Bayan Obo deposit in Inner Mongolia, China.
A new niobium mineral from Bayan Obo
Xianhuaite-(Ce) is especially interesting for collectors of new minerals: its rare-earth and niobium chemistry expands the known structural diversity of natural oxides.
Collecting and care
Protect small grains from impact and acids; retain the analytical record and do not infer composition from brown colour alone.
