Outstanding white and yellowish acicular and hairy crystals of the extremely rare organic mineral urea (CO(NH2)2) from one of the few known localities worldwide (Planet Mine, Planet, La Paz County, Arizona, United States of America). Very rich specimen for the quantity of urea present. Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Urea
Urea is an IMA-recognized mineral species in the organic mineral class, with the chemical formula CO(NH₂)₂.
It crystallizes in the tetragonal crystal system (space group P-42_1m).
Key properties: specific gravity 1.33; optically uniaxial.
IMA symbol Ur, IMA status: approved, named in 1972.
Derived from bat guano and urine, stable only under very arid conditions.
It is found associated with Ammonian aphthitalite, weddellite, phosphammite.
Its name comes from the Greek for urine, in which urea was first found.