Rare earth metals are actually not that rare. They are just more difficult to extract, or are found in problematic locations and concentrations in the earth’s crust. These metals are in the Lathinide group on the periodic table of elements, with Scandium and Yttrium added.
They have any of five special properties which are catalytic, chemical, electrical, metallurgical, nuclear, magnetic or optical, making rare earth metals valuable for application in a host of advanced technological functions.
“Lazy College Professors Never Produce Sufficiently Educated Graduates To Dramatically Help Executives Trim Yearly Losses!” What?! This is the mnemonic that is used to remember the rare earth metals, or the lanthanoids
Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium,Europium, Gadolinium,Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, and Lutetium are the rare earth metals in question.
These metals range in color from silver to iron gray, and are generally soft, malleable, compoundable and reactive. They are especially reactive when “finely divided” or when heat is applied. The lowest heating point is 798 degrees C for Cerium, with the highest at 1,663 degrees C for Lutetium.
Now. What are they used for?
Almost 70% of them are used in catalytic conversion…not just the catalytic conversion for reducing smog from our cars, but in refining petroleum products through Catalysis.
12% are used in permanent magnets, or persistent magnets that maintain their own magnetic field.
7% are used in glass polishing and ceramics. This results in fibers, thin films, coatings, preceramic matter, and ceramic adhesives.
7% are used in metallurgy, with promising applications being developed in creating new compounds, coatings, or other adaptations of metal substances.
The rest are used as phosphors and in other applications.
From baseball bats to microwave filters; from the expensive linings in our car’s catalytic converters; from our batteries to miniature nuclear batteries; and from industrial ceramic coatings to our crafty ceramic pigments; these not so rare, but valuable substances have become a regular part of our lives as well as of the most advanced scientific and industrial operations.
In summary, these not so rare metals are now revolutionizing technology with their incredible properties and benefits. But there are some interactions with the human body that can be either problematic or beneficial. Some lathanoids can interfere with calcium channels, while others can affect metabolic processes by altering or inhibiting the actions of certain enzymes. Other reactions can include regulation of synaptic transmission or blocking of receptors.
Wikipedia Interactive Periodic Table Of Elements
Seeking Alpha, “Rare Earth Metals Not So Rare But Valuable” Nov 2008