"For main applications like rare-earth magnets and glass catalysts, the [demand] increase is from 10 to 15 percent a year," Ishanov said. Japan's consumption of the metal products is about 40,000 metric tons a year at present, he said. China's move to constrain supply has soured diplomatic relations with Japan, which is moving to secure supplies from Vietnam, the United States, India and Germany. Rare earths are a group of 17 chemically similar metallic elements, including lanthanum, cerium, neodymium and europium. The elements are used in radar, high-powered magnets, mini hard drives in laptop computers, catalytic converters for vehicles, electric-car batteries and wind turbines. Prices of neodymium oxide, which is used in mini hard drives in laptops and headphones in Apple's iPod, have surged fourfold to $80 a kilogram from $19.12 in 2009, according to Lynas Corporation.