25 Oct 2010
The Chinese government has also been imposing tighter and tighter restrictions on general exports of the minerals, citing growing domestic demand. The export quota for the second half of 2010 has been reduced by 72%.
Despite the name, rare earths aren't uncommon, but are expensive and sometimes dangerous to extract.
China currently produces an estimated 97% of the world's supply. If China continues to ban exports, it could take between two and five years to set up mines in other countries and even longer for the supply chain to be fully repaired.