Noun
A rare white earthy substance, consisting of the oxide of thorium; -- formerly called also thorina.
Source: Webster's dictionaryThe melting point of thoria is 3300 °C – the highest of all known oxides; only few substances have higher melting points. Source: Internet
This property of thoria is used in mantles of portable gas lights, including natural gas lamps, oil lamps and camping lights. Source: Internet
Sometimes thorium nitrate is used instead, because it will thermally decompose to thoria at high temperatures. Source: Internet