Thorium Dioxide (ThO2), also called thorium(IV) oxide, is a highly insoluble thermally stable Thorium source. It is a crystalline solid and often white or yellow in color. Also known as thoria, it is produced mainly as a by-product of lanthanide and uranium production. Thorianite is the name of the mineralogical form of thorium dioxide. Thorium is highly valued in glass and ceramic production as a bright yellow pigment because of its optimum reflectanceHigh Purity (99.999%) Thorium Oxide (ThO2) Powder at 560 nm. Oxide compounds are not conductive to electricity.