An Etymological Dictionary of Astronomy and Astrophysics

A black crystalline solid (UO_{2</SUB) which occurs in several minerals including → pitchblende,
carnotite, and autunite and is used chiefly as a source of nuclear energy by fission of the radioisotope uranium-235. After the → uranium hexafluoride is enriched, a fuel fabricator converts it into uranium dioxide powder and presses the powder into fuel pellets.}

See also: → uranium; → dioxide.