and this from TD

Analysts warned that investors should be careful before investing in rare earth miners on a speculative basis.

"Its all very theoretical," said Hallgarten & Company analyst Christopher Ecclestone of the junior miners. "These stocks are going up because the products are going up in price, but none of these companies have any products that they sell."

Canadian-based Great Western and Neo Material Technologies both produce rare earth metals and alloys from concentrate mined in China.

Beijing has already cut export quotas for the second half of 2010 by 70 percent, and last month China halted exports of rare earths to Japan over a political row.

Ecclestone said that any blocked shipments to the United States or Europe would likely be geared at stopping Japan, the world's largest consumer of rare earths outside China, from accessing the supply.

"There may also be a suspicion that ... cheating is going on," said Ecclestone, "Whereby a German trading company or a Swiss trading company was buying the rare earths from China and then selling them to Japan."