Cerium(III) oxalate - Ce2(C2O4)3
Cerium oxalate is a bright white compound of cerium(III). Cerium(III) ion is colorless and solid compounds of cerium(III) usually are white. This is in strong contrast with the deep yellow color of cerium(IV) ions.
Cerium(III) oxalate is nearly insoluble in water. It is not easily oxidized, but with sufficiently strong oxidizers it is possible to oxidize it to carbon dioxide and cerium(IV), resulting in a deep yellow solution.