“There’s gold, er, rare-earth metals in them thar hills, boys!”

It turns out that the waste from many gold mines contains rare-earth metals. Why is that important? According to this article by the Associated Press, "Two years ago, China raised prices — in the case of neodymium, used to make Prius electric motors stronger and lighter, from $15 a kilogram in 2009 to $500 in 2011, while dysprosium oxide used in lasers and halide lamps went from $114 a kilogram in 2010 to $2,830 in 2011. It's also about the time China cut off supplies to Japan, maker of the Prius, in a dispute over international fishing territory." So it's important that new sources of these rare-earth metals are found.

The AP explains that miners in the early days of the West were looking for gold, silver and copper. They didn't even know what rare-earth metals were; even if they did, these metals are much more difficult to extract. With China raising the prices for political reasons, companies are looking for new sources and they have found them in an unexpected place.

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The quote that the title is based on was originally from "The American Claimant" written by Mark Twain in 1892. However, there is some indication that this phrase was originally spoken by M.F. Stephenson describing the hills around Dahlonega, Georgia.

From Wikipedia, here are the 17 rare-earth metals. They get the name "rare earth" because they are widely distributed and not concentrated in ores as are gold, silver and copper. Also, they tend to bind to each other. This makes these metals harder to concentrate and refine.

Note that indium, also mentioned in the story, is not considered a rare-earth metal. Also, I doubt that AP Style calls for capitalizing element names. Oops.

Updated July 23 to improve formatting.