Thorianite
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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. Wikipedia
Optical properties: Isotropic
Cleavage: Poor/Indistinct
Crystal class: Hexoctahedral (m3m); H-M symbol: (4/m 3 2/m)
Crystal habit: Cubic crystals, usually rounded to some degree in detrital deposits
Crystal system: Isometric
Formula (repeating unit): Thorium oxide, ThO2
Mohs scale hardness: 6.5 – 7