Use
Cerium, a soft, silvery and ductile metal, is the most abundant of the rare earth elements. It also has numerous applications. For example, cerium (III) oxide is used as a catalyst for the oxidation of CO emissions from motor vehicles, while cerium oxide (IV) is used for precision polishing of optical componets. Cerium compounds are also used in producing glass. Cerium can also be add to aluminum, iron and magnesium alloys to their properties.