What is Xiangjiangite?
Xiangjiangite is a very soft, strongly hydrated uranium phosphate-sulfate associated with oxidised uranium deposits and rare autunite-related assemblages.
Mineralogy and structure
Reference formula: (Fe3+,Al)(UO2)4(PO4)2(SO4)2(OH)·22H2O. Xiangjiangite is strongly hydrated and compositionally variable between iron and aluminium. Public crystallographic data remain incomplete or pseudotetragonal, so no artificial lattice is shown. Xiangjiangite is classified with phosphates and has tetragonal crystal symmetry. Typical hardness is 1–2 on the Mohs scale and specific gravity is approximately 2.8–3.1.
Colour, lustre and habit
Typical colours include yellow, pale yellow, greenish yellow. The usual fibrous, crusty, radiating habit and silky, pearly, dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Xiangjiangite forms in or is associated with secondary oxidation zones of uranium ores, phosphate-sulfate cavities and mine fractures. Important documented localities include the Jinyinzhai Mine in Hunan, China, France, Germany and other uranium districts.
A rare yellow uranium phosphate-sulfate
Xiangjiangite is a specialist reference mineral whose value lies in its chemistry and locality. Its fragile hydrated nature makes secure documentation more important than display size.
Collecting and care
Radioactive and extremely soft: keep sealed, dry and away from dust, heat and casual handling; follow radiation-safety procedures.
