Cerium is a gray metal used in making many different alloys and specialty glass and it is the 26th most common element found in the Earth's crust. Cerium is the most abundant rare Earth metal; it is abbreviated as Ce and found in the sixth row of the periodic table of elements.
Isolated by Sweden's Carl Gustav Mosander in 1839, cerium received its name in honor of the asteroid Ceres, which was discovered in 1801. Its occurrence in nature is about as common as copper or zinc. Cerium must be handled with care because it is reactive to oxygen, water, hydrogen, acid, bases and metal. It is used in glass, ceramics, catalytic systems and dental materials.