Every day, we use products that are built using “rare earths”—a group of 17 elements that are, as the name suggests, very rare. They’re used to make everyday items such as rechargeable batteries, LED lights and display panels, as well as larger products such as wind turbines. Now, it turns out, Japan has an estimated 16 million tons of the stuff on its turf. And researchers claim the trove might be enough to supply the world with metals such as yttrium and europium on a “semi-infinite basis.”