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 1008 (OTTO) Cerium powder, -200 mesh, 99.9% Cas 7440-45-1 - used in ferrocerium lighters for its pyrophoric properties.