Cerium is a soft, ductile, silvery-white metallic chemical element with symbol Ce and atomic number 58. Cerium tarnishes when exposed to air, and it is soft enough to be cut with a knife
C 1802 (OTTO) Cerium, powder, 99.9% Cas 7440-45-1 - used as alloying element in aluminum to create castable eutectic alloys, Al-Ce alloys with 6–16 wt.% Ce, to which Mg and/or Si can be further added; these alloys have excellent high temperature strength.