Trade statistics have revealed the country's import of rare earth minerals from China surged by more than 50 percent in the January-November period last year from the same period in 2009 — even though it plunged by two-thirds in the October-November period due to export restrictions by Beijing.

China suspended exports in September, only to resume them a few weeks later. Although there has been no news that production of smart phones and hybrid cars has been stalled because of a shortage of rare earth metals, Japanese trading houses and firms are trying to reduce their reliance on China.

And some metal traders say the worst is yet to come.