China's control over supplies of so-called rare-earth elements includes a group of 17 metallic elements with magnetic properties suited for high-tech applications such as computer hard drives and digital cameras. Rare-earth elements are also key to "green" technology: Energy-efficient light bulbs use europium and yttrium, while hybrid car batteries and wind-power turbines use neodymium. While rare-earth ore deposits are found around the globe, China's dominates the mining and processing of these elements. According to an April 2010 Government Accountability Office report, China now produces approximately 97% of the world's rare-earth oxides, the raw materials that can be further refined into metals and blended into alloys that can be made into finished components.
Rare Earth Oxides
Rare-earth metals have important military applications because of their magnetic strength, which allows for extraordinary miniaturization of components. The fins that steer precision bombs, for instance, have samarium-cobalt permanent magnet motors. The motors that run the rudder and tail fins on a high-performance fighter aircraft like the Air Force F-22 Raptor are built with lightweight, rare-earth magnets. Neodymium is found in the solid-state lasers used to designate targets. (WSJ, 9/23/2010)