Behind the devices that shape modern life is an array of natural and human-made materials. One such component of smartphones and computers are rare earth metals, a group of 17 elements that, because they aren't found in concentrated deposits, require energy-intensive and toxic methods to extract. While recycling rare earth metals from used devices is one way to relieve strained supply chains and reduce environmental damage, the fundamental chemistry required for efficiently separating and reusing these metals remains a challenge.