[yefragetuwrabrumuy]

The twist here is not that the 17 rare earths are rare, but that refining them is extremely hard and extremely polluting.

The hard part is that chemically, many of them are very similar, so separating them is a major pain.

http://en.wikipedia.org/wiki/Rare_earth_element#List

“The Chinese have also used sulfuric acid refining techniques that generate 9,600 to 12,000 cubic meters of gas “laden” with flue dust concentrate, hydrofluoric acid, sulfur dioxide, and sulfuric acid to produce one ton of rare earth elements. Chinese refining processes also produce large amounts of liquid and solid waste; they estimate that after refining one ton of rare earth elements, approximately 75 cubic meters of acidic waste water and about one ton of radioactive waste residue are produced.

“China produced over 130,000 metric tons of rare earth elements in 2008. Combining this figure with the figure for waste generation estimates that production yields very large amounts of waste - 1.2 billion to 1.6 billion cubic meters of waste gases per year, and 9.8 million cubic meters of acidic waste water.”

[P.O.E.]

refining them is ... extremely polluting

For that very reason, I say let China do it.

[GeronL]

The twist here is not that the 17 rare earths are rare, but that refining them is extremely hard and extremely polluting

So if China announces they are going to limit production because of the environment, then that would be okay with the same bureaucrats??