Rare earth elements have wide commercial applications. The light rare earths - lanthanum, cerium, praseodymium and neodymium - are the focus of this article. Lanthanum
Lanthanum gets its name from the Greek word lanthanein, which means "to escape notice." It was discovered in 1839 when it was extracted from impure cerium nitrate. In 1929, it was isolated in its pure form. Lanthanum is found in rare-earth minerals, principally in the ores monazite and bastnasite. Misch metal, which is used in making lighter flint, also contains lanthanum. Compounds containing lanthanum are used in carbon lighting, particularly in motion picture studio lighting and projection. Certain compounds are used to make special glass, often optical glass. An addition of lanthanum can help create nodular cast iron as well. In modern commercial applications, lanthanum is prevalent. Toyota's Prius hybrid car contains approximately 10 pounds of lanthanum overall, for example. Nickel-lanthanum batteries are a very efficient alternative to traditional car batteries. Hybrid car batteries and batteries for small Chinese mopeds both use lanthanum, and there is not enough of the mineral to meet current demand. As hybrid cars become more common, the demand for lanthanum will increase even more. The market for lanthanum is thriving, and it is currently possible to create it in a lab by reducing the anhydrous fluoride with calcium. Cerium
Cerium, the most abundant of the rare-earth minerals, was discovered in 1803 and named after the asteroid Ceres. Four isotopes of cerium occur in nature. Cerium is found in several minerals, including allanite, monazite and cerite. Deposits of cerium itself have been found in Brazil, India and southern California. Like lanthanum, cerium is used extensively in the film industry for carbon lighting. It, too, is in compounds that can create nodular cast iron. It also has applications in the manufacture and treatment of glass, as well as cigarette lighters and self-cleaning ovens. Cerium is added to glass to color it and increase its absorption of ultraviolet light. This application is important in building, as windows that do not allow much ultraviolet light to enter are valuable objects. It also colors enamels. Added to steel or iron, it increases the metals' strength. Cerium is a component in fluorescent lighting and can polish glass. Its many uses create a fairly high demand for cerium, which the market can meet due to the mineral's relative abundance in the world.