What is Uranotil?
Uranotil is a historical uranium-silicate name closely related to uranophane, used for yellow hydrated secondary material from oxidised uranium deposits.
Mineralogy and structure
Reference formula: Ca(UO2)2(SiO3OH)2·5H2O. Uranotil is retained as a distinct searchable guide label for historical and trade literature, but no separate verified COD lattice is assigned in this batch. It is discussed alongside uranophane rather than given a fabricated structure; all uranium-bearing material is radioactive. Uranotil is classified with silicates and has monoclinic crystal symmetry. Typical hardness is 2.5–3 on the Mohs scale and specific gravity is approximately 3.8–4.0.
Colour, lustre and habit
Typical colours include yellow, greenish-yellow, brownish-yellow. The usual fibrous, crusty, radiating habit and silky, dull, vitreous lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Uranotil forms in or is associated with oxidised uranium veins, weathered mine workings and secondary silica-rich alteration zones. Important documented localities include Central Europe, France, the United States, Canada and Australia.
A historical name in the uranium-silicate story
Uranotil is useful when older labels appear in collections and mine literature. Linking it conceptually to uranophane helps prevent duplicate interpretation while preserving the historical record.
Collecting and care
Radioactive and fragile: keep enclosed, dry and away from casual handling; do not cut, grind, wash or generate dust.
