Ghost of a flea

A tightening supply of rare-earth elements such as neodymium, samarium, and dysprosium used in permanent magnets, catalysts, glass, polishing, and a broad range of other applications has caught the attention of policymakers in Washington, stimulated efforts to tap rare-earth deposits in North America and Australia, and spurred R&D on alternative materials.

The US and the rest of the world have relied on China for nearly all of their rare-earth supplies. But China has been curtailing its exports in recent years, conserving the elements for its own manufacturers. That has prompted fears of an impending shortage in the West.