Factbox: Five facts about rare earth elements

(Reuters) - China said it would cut its export quotas for rare earth minerals more than 11 percent in the first half of 2011, further shrinking supplies of metals needed to make a range of high-tech products.

Here are five facts about rare earth elements:

* There are 17 so-called rare earth metals. They have names like europium and cerium, and are used in a range of products from MP3 players and computer hard drives to hybrid cars, wind turbines, light bulbs and coffee makers.

* China produces about 97 percent of the world’s rare earth elements. So its announcement on Tuesday that it was again cutting its export quota sent shockwaves through the markets and -- at least temporarily -- boosted the shares of rare earth producers in other countries, whose ranks include Molycorp Inc. of the United States, Rare Element Resources Ltd of Canada and Lynas Corp of Australia.

* Rare earth metals are not as rare as the name suggests. The United States once dominated global production and has a large deposit in Mountain Pass, California, at a mine owned by Molycorp. But in the 1990s, China, which also has large deposits, began flooding the market and sending prices tumbling. Between 1990 and 2006, the average price of rare earth metals fell about 75 percent.

* Production at Molycorp’s mine, which was once owned by a unit of the oil company Chevron Corp, stopped in 2002, in part because of the price collapse. The shutdown has increased the rarity of these metals, and China’s export quotas have further tightened supplies, but the U.S. Geological Survey says global supplies are plentiful.

* In addition to Molycorp’s Mountain Pass mine in California, other mines under development outside China include: Great Western Minerals facility in Steenkampskraal, South Africa; Avalon Rare Metals’ operation in Nechalacho, Canada; Lynas Corp’s facility in Mount Weld, Australia; and Arafura Resources mine in Nolans, Australia .

Sources: Company websites, U.S. Geological Survey

Reporting by James B. Kelleher in Chicago. Editing by Robert MacMillan