Thorium dioxide (ThO2), nke a na-akpọkwathorium (IV) oxide, bụ isi iyi Thorium kwụsiri ike nke ukwuu. Ọ bụ kristal siri ike ma na-acha ọcha ma ọ bụ odo na agba. A makwaara dị ka thoria, a na-emepụta ya karịsịa dị ka ngwaahịa sitere na lanthanide na mmepụta uranium. Thorianite bụ aha ụdị nke thorium dioxide. A na-eji Thorium kpọrọ ihe nke ukwuu na iko na mmepụta seramiiki dị ka pigmenti na-acha odo odo na-egbuke egbuke n'ihi nlegharị anya ya kachasị dị ọcha (99.999%) Thorium Oxide (ThO2) ntụ ntụ na 560 nm. Ngwakọta oxide anaghị eduzi ọkụ eletrik.