Rare earth metals are not as rare as they seem. Rare metals are used in everything from tablets and TVs to hybrid cars and wind turbines.
Why are they called "rare" metals? This is because there are 17 elements that rarely exist in their pure form. Instead, they mix intensely with other minerals in the ground, making them expensive to mine.
Below are some ways to use each rare earth element:
Scandium: Used in some sports equipment, including aluminum baseball bats, bicycle frames and lacrosse sticks, and in fuel cells.
Yttrium: Provides color in many television picture tubes. It also conducts microwave and sonic energy, mimics diamond gemstones, and strengthens ceramics, glass, aluminum and magnesium alloys.
Lanthanum: One of several rare earths used to make carbon arc lamps, which are used in studio and projector lamps in the film and television industry. Also found in batteries, lighter flints, and special types of glass such as camera lenses.
Cerium: The most abundant of all the rare earth metals. Used in catalytic converters and diesel fuel to reduce carbon monoxide emissions from vehicles. Also used in carbon arc lamps, flints, glass polishers, and self-cleaning ovens.
Pseodymium: It is mainly used as an alloying additive for magnesium and is used in the production of high strength metals for aircraft engines. It is also used as a signal amplifier in fiber optic cables and as a hard glass in welder's goggles.
Neodymium: Mainly used to make powerful neodymium magnets used in computer hard drives, wind turbines, hybrid cars, headphones and microphones. Also used to tint windows and make lighters and welder's goggles.
Promethium: Not found naturally on Earth; it must be produced artificially by fissioning uranium. Added to some types of glow-in-the-dark paints and nuclear-powered microbatteries, possibly used in portable X-ray equipment.
Samarium: Blended with cobalt to create permanent magnets with the highest resistance to demagnetization of any material known. Necessary for the manufacture of "smart" missiles; also used in carbon arc lamps, silica, steel, and some types of glass.
Eurium: the most reactive of all the rare earth metals. It has been used for decades as a red phosphor in televisions and more recently in computer monitors, fluorescent lights, and some types of lasers, but otherwise it has little commercial use.
Gadolinium: used in some control rods in atomicpower plants. It is also used in medical applications such as magnetic resonance imaging (MRI) and in industry to improve the machinability of iron, chromium and various other metals.
Terbium: Used in some solid-state technologies, from advanced sonar systems to small electronic sensors and fuel cells designed to operate at high temperatures. Also produces laser beams and green phosphor in television tubes.
Dysprosium: used in some control rods in nuclear power plants. It is also used in some types of lasers, high-intensity lighting, and to increase the coercive force of powerful permanent magnets, such as in hybrid electric vehicles.
Holmium: has the highest magnetic strength of any known element and is therefore used in industrial magnets and some nuclear control rods. Also used in solid state lasers and helps color cubic zirconia and some types of glass.
Erbium: used as a photofilter and signal booster (aka "impurity") in fiber optic cables. Also used in some nuclear control rods, metal alloys, and for coloring specialty glass and porcelain in sunglasses and inexpensive jewelry.
Thulium: The rarest of all naturally occurring rare earth metals. It is used in some surgical lasers. It is also used in portable x-ray technology after being irradiated in nuclear reactors.
Ytterbium: Used in some portable x-ray machines, but has limited commercial use. Among its specialized uses, it is used in certain types of lasers, seismic strain gauges, and as a dopant in fiber optic cables.
Lutetium. Used primarily for specialized purposes such as determining the age of meteorites or performing positron emission tomography (PET) scans. It is also used as a catalyst in the "cracking" process of petroleum products in refineries.