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

Setting off speculation that China is manipulating exports to punish certain trade partners, Beijing announced in July it was slashing its six-month export quota of so-called 'rare earths' by 72 percent. Speculation continued this week with reports of an expanding embargo of the minerals.

But the so-called "rare earths" are neither rare nor does China have a lock on them. Although China produces 97 percent of the world's rare earths, it contains only 30 percent of the world's supply. The United States, Russia, and Australia all have significant reserves of the 17 elements essential in semiconducters, lasers, and other high-tech gadgets.

While mining them has proved uneconomical at usual world prices and environmentally harmful, that may be changing. Click through the following slides to read how rare earths are important to your daily life.

- Stephen Kurczy, Staff writer

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James Hetfield of Metallica performs during a concert at the Olympic Stadium in Stockholm in 2007. The concert may not have happened without the rare earth metal of neodymium, which is used in microphones and guitar pick-ups. (Bertil Ericson/Reuters)

3. Neodymium

You'll never think of a rock concert the same way. Neodymium (atomic No. 60) is most commonly used in magnets for microphones, loudspeakers, in-ear headphones, and guitar and bass guitar pick-ups.

It's also used in modern weapons, sparking concerns over China's corner on the market, Bloomberg reported in September:

“It’s a seller’s market now,” says Bai Baosheng, 43, puffing a cigarette in his office in Baotou, China, where his company sells bags of powder containing a metallic element known as neodymium, vital in tiny magnets that direct the fins of bombs dropped by US Air Force jets in Afghanistan.
... Neodymium, a silvery metal, is essential in a magnetic alloy developed separately by engineers at General Motors Co. in Detroit and Sumitomo Special Metals Co. in Japan in the 1980s. The magnets are now in millions of stereo speakers, computer disk drives, and motors.

Bloomberg recently reported that the price of neodymium has doubled since July to $92 a kilogram, according to Metal-Pages, pushing up the cost of magnets.