Tags: Chemical Substance, Mineral.
Thorianite is a rare thorium oxide mineral ThO2. It was originally described by Ananda Coomaraswamy in 1904 as uraninite but recognized as a new species by Wyndham R. Dunstan. It was so named on account of its high percentage of thorium; it also contains the oxides of uranium lanthanum cerium praseodymium and neodymium. Helium is present and the mineral is slightly less radioactive than pitchblende but is harder to shield due to its high energy gamma rays.
