13 March 2012 Last updated at 15:06 ET

What are 'rare earths' used for?

Rare earth elements are chemically similar and are sometimes used in similar ways

"Rare earths" are a group of 17 chemically similar elements crucial to the manufacture of many hi-tech products. Despite their name, most are abundant in nature but are hazardous to extract. Most "rare earth" elements have uses in several different fields, as well as those listed below.

Neodymium

This is used to make powerful magnets used in loudspeakers and computer hard drives to enable them to be smaller and more efficient. Magnets containing neodymium are also used in green technologies such as the manufacture of wind turbines and hybrid cars.

Lanthanum

This element is used in camera and telescope lenses. Compounds containing lanthanum are used extensively in carbon lighting applications, such as studio lighting and cinema projection.

Cerium

Used in catalytic converters in cars, enabling them to run at high temperatures and playing a crucial role in the chemical reactions in the converter. Lanthanum and cerium are also used in the process of refining crude oil.

Yttrium is used in the process of generating colour displays on devices such as television screens

Praseodymium

Used to create strong metals for use in aircraft engines. Praseodymium is also a component of a special sort of glass, used to make visors to protect welders and glassmakers.

Gadolinium

Used in X-ray and MRI scanning systems, and also in television screens. Research is also being done into its possible use in developing more efficient refrigeration systems.

Yttrium, terbium, europium

Important in making televisions and computer screens and other devices that have visual displays as they are used in making materials that give off different colours. Europium is also used in making control rods in nuclear reactors.

Source: British Geological Survey, Royal Society of Chemistry