Top 5 'rare earth' minerals: What are they?

The so-called 'rare earths' are neither rare nor does China have a lock on them. The following five rare earth elements are used in daily life.

4. Cerium

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    Dave Mead of Massachusetts stands by the projectors at the Wellfleet Drive-In, which in the 1990s was still using carbon arc lights to project the image. He has to change the rods every 4 reels or after 80 minutes. The rare earth element cerium is used in carbon-arc lighting.
    Melanie Stetson Freeman/CSM
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Common as copper, cerium (No. 58 on the periodic table) is one of the most abundant of the rare earth metals.

It is often converted into cerium oxide, which is known as "optician's rouge" for its ability to polish glass and semiconductors. Cerium oxide (CeO2 ) is also essential in catalytic converters, helping to turn smog-causing molecules into carbon dioxide, as well in the massive carbon-arc lighting used on movie sets.

Bloomberg reported recently that cerium oxide prices rose to $36 per kilogram Oct. 19 from about $4.70 a kilogram on April 20, according to Metal-Pages.

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