Fears about Chinese supplies of vital rare earth elements have sent the shares of small mining companies soaring, a surge that executives and analysts warn is turning into a bubble.
China, responsible for about 97 per cent of global rare earth production, has cut exports of the minerals used in high-tech goods from PCs to electric cars, driving up prices of the commodities and creating a worldwide hunt for other sources.
An index of rare earth company shares produced by Kaiser Bottom-Fish Online, a research service, has risen 12-fold since the end of 2008, and 35 per cent in the past month.
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