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The What? And Why? Of Rare Earth Metals

February 10, 2011

Over the past few months, there’s been a buzz surrounding rare earth metals. These are metals such as europium, lanthanum, neodymium and 14 others found in small concentrations attached to other metals and resource deposits. They’re actually not that rare, just expensive and difficult to pull out of the ground.

These naturally occurring elements are essential in everything from wind turbines to lasers to iPads.

Rare earths are a conundrum for the environmentally conscious—they hold the key to green energies but create toxic waste when being separated away from other elements. “Just one wind turbine generating 3 megawatts of electricity requires 600 kilograms of rare earths for its magnets,” a source told the United Kingdom’s Guardian newspaper.

Electric and hybrid cars can contain more than twice as much rare earth metals as a standard car. This image from the NY Times breaks down how these metals make up critical elements of a Prius.

Currently, China controls 97 percent of the world’s production of rare earth metals. In October 2010, the country cut exports of the metals by 70 percent, disrupting manufacturing in Japan, Europe and the U.S., and sending the prices of these metals up 40 percent.

China currently controls production but the country only has 37 percent of the world’s estimated reserves. This second visual published by the NY Times shows the identified rare earth metal deposits around the globe.

The U.S. used to be a top manufacturer of rare earth metals back in the 1960s, but eight years ago environmental infractions shut down the Mountain Pass, California mine, the largest deposit of rare earth metals outside of China. Currently, there are efforts to restart production at the mine but several hurdles must be cleared first. Today, the U.S. imports 87 percent of its rare earths from China.

Other countries such as Kenya, South Africa, Malawi and Greenland are believed to be sitting atop large deposits of rare earth metals as well.

Increased production outside of China is required in order to meet increased demand. Estimates show that global demand is expected to reach 205,000 tons by 2015, according to the Guardian. As high tech becomes a greater part of people’s lives in both the developing and emerging world, the importance of these metals should continue to rise.


A table listing the seventeen rare earth elements, their atomic number and symbol, the etymology of their names, and their main usages (see also Lanthanide#Technological_applications) is provided here. Some of the rare earths are named for the scientists who discovered or elucidated their elemental properties, and for their geographical discovery.

Z↓ Symbol↓ Name↓ Etymology Selected Usages
21 Sc Scandium from Latin Scandia (Scandinavia), where the first rare earth ore was discovered. Light Aluminium-scandium alloy for aerospace components, additive in Mercury-vapor lamps.[4]
39 Y Yttrium for the village of Ytterby, Sweden, where the first rare earth ore was discovered. Yttrium-aluminum garnet (YAG) laser, YBCO high-temperature superconductors, yttrium iron garnet (YIG) microwave filters.[4]
57 La Lanthanum from the Greek “lanthanein”, meaning to be hidden. High refractive index glass, flint, hydrogen storage, battery-electrodes, camera lenses, fluid catalytic cracking catalyst for oil refineries
58 Ce Cerium for the dwarf planet Ceres. Chemical oxidizing agent, polishing powder, yellow colors in glass and ceramics, catalyst for self-cleaning ovens, fluid catalytic cracking catalyst for oil refineries
59 Pr Praseodymium from the Greek “prasios”, meaning leek-green, and “didymos”, meaning twin. Rare-earth magnets, lasers, core material for carbon arc lighting, colourant in glasses and enamels, additive in Didymium glass used in welding goggles,[4] ferrocerium firesteel (flint) products.
60 Nd Neodymium from the Greek “neos”, meaning new, and “didymos”, meaning twin. Rare-earth magnets, lasers, violet colors in glass and ceramics, ceramic capacitors
61 Pm Promethium for the Titan Prometheus, who brought fire to mortals. Nuclear batteries
62 Sm Samarium for Vasili Samarsky-Bykhovets, who discovered the rare earth ore samarskite. Rare-earth magnets, lasers, neutron capture, masers
63 Eu Europium for the continent of Europe. Red and blue phosphors, lasers, mercury-vapor lamps, NMR relaxation agent
64 Gd Gadolinium for Johan Gadolin (1760–1852), to honor his investigation of rare earths. Rare-earth magnets, high refractive index glass or garnets, lasers, x-ray tubes, computer memories, neutron capture, MRI contrast agent, NMR relaxation agent
65 Tb Terbium for the village of Ytterby, Sweden. Green phosphors, lasers, fluorescent lamps
66 Dy Dysprosium from the Greek “dysprositos”, meaning hard to get. Rare-earth magnets, lasers
67 Ho Holmium for Stockholm (in Latin, “Holmia”), native city of one of its discoverers. Lasers
68 Er Erbium for the village of Ytterby, Sweden. Lasers, vanadium steel
69 Tm Thulium for the mythological northern land of Thule. Portable X-ray machines
70 Yb Ytterbium for the village of Ytterby, Sweden. Infrared lasers, chemical reducing agent
71 Lu Lutetium for Lutetia, the city which later became Paris. PET Scan detectors, high refractive index glass
  1. Rider I
    April 30, 2011 at 2:18 pm
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