Cerium is named for the asteroid Ceres, which was discovered in 1801 only two years before this element. Cerium is the most abundant of the metals of the so-called rare earths. It is found in a number of minerals including allanite, monazite, bastnasite, cerite and samarskite. Monazite and bastnasite are the two most important sources of cerium. Large deposits of monazite are found on the beaches of India and in river sands in Brazil. Large deposits of allanite and bastnasite are found in the western U.S. Metallic cerium is prepared by metallothermic reduction techniques, such as reducing cerous fluoride with calcium, or by electrolysis of molten cerous chloride or other cerous halides. Cerium is an iron-gray, lustrous metal. The metal is a component of misch metal, which is extensively used in the manufacture of pyrophoric alloys for cigarette lighters. The oxide is an important constituent of incandescent gas mantles and it is emerging as a hydrocarbon catalyst in "self-cleaning" ovens.