At mines like this one in Jiangxi Province, China produces 95 percent of the world's rare-earth minerals, a key resource for the future of energy.
(Related: "While Rare-Earth Trade Dispute Heats Up, Scientists Seek Alternatives")
With tongue-twisting names like dysprosium, yttrium, and neodymium, these 17 metals are found in products ranging from cell phones and computers to medical devices and jet engines. They play an important role in the coatings, magnets, and phosphors used in green technology, such as photovoltaic thin film panels, fluorescent lighting, wind turbines, and electric vehicles. On March 13, the United States, Japan, and European Union filed a World Trade Organization complaint against China for restricting exports of these minerals and driving up prices. As trade officials try to find a resolution, scientists around the world are searching for substitutes.
(Related: "Pictures: A Rare Look Inside China's Energy Machine")
This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.