Factbox: What are rare earth elements?

TORONTO (Reuters) - Rare earth elements are used in a wide range of consumer products, from iPhones to electric car motors.

Demand is growing, fueled by green technology. At the same time, supplies are getting tight. China, which produces over 90 percent of the world's supply, has cut exports by almost half this year.

A looming global shortage has pushed numerous Canadian miners into the spotlight. Here are some facts on this elusive group of 17 metals:

WHAT ARE RARE EARTHS?

Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium.

WHAT ARE RARE EARTHS USED IN?

Rechargeable batteries for electric and hybrid cars, advanced ceramics, magnets for electric car motors, computers, DVD players, wind turbines, catalysts in cars and oil refineries, computer monitors, televisions, lighting, lasers, fiber optics, glass polishing, superconductors, and weapons.

THE iPHONE CONNECTION

Rare earths make for smaller, lighter batteries and motors. The drive to miniaturization was first popularized by the Sony Walkman personal cassette tape player. Rare earths are now key to making handheld devices like Apple's iPhone and Research In Motion's BlackBerry.

BIGGEST CONSUMERS

China and Japan. Global demand is forecast to grow rapidly as demand for green products increases.

BIGGEST PRODUCERS

China produces over 90 percent of global supplies. China mined 120,000 tonnes in 2008, followed by India, which produced 2,700 tonnes, Brazil and Malaysia.

BIGGEST DEMAND

The demand for dysprosium, terbium, neodymium, praseodymium and europium is set to grow by a minimum of 8 percent a year.

Electric vehicle demand for dysprosium, neodymium and praseodymium is set to grow by an average of 790 percent in the next five years.

BIGGEST MINES UNDER DEVELOPMENT, OUTSIDE CHINA

Great Western Minerals, Steenkampskraal, South Africa

Avalon Rare Metals, Nechalacho, Canada

Molycorp, Mountain Pass, U.S.

Lynas Corp , Mount Weld, Australia

Arafura Resources, Nolans, Australia

Sources: U.S. Geological Survey, company web sites, Byron Capital Markets

(Reporting by Julie Gordon; Additional reporting by Steve Gorman and Sonali Paul; Editing by Michael Perry and Paul Tait)