Dysprosium

Dysprosium is a silvery rare-earth metal discovered by Paul-Émile Lecoq de Boisbaudran in 1886. Separating it from its neighbors was so tedious that he named it from the Greek dysprositos, meaning hard to get at. Most of it comes from clay deposits in southern China and Myanmar.

Its key job is inside the neodymium magnet. These magnets are very strong at room temperature but weaken as they heat up. Swapping a few percent of the neodymium for dysprosium makes the magnet far more resistant to losing its magnetism when hot. That matters in electric car motors and wind turbines, which run warm for years. Because it is scarce, makers often place it only along the edges of the magnet's tiny crystals.