Neodymium was isolated in 1885 by Carl Auer von Welsbach at the same time as praseodymium, when he separated the supposed element didymium into two. He named it neodymium, from the Greek neos didymos, new twin. Neodymium is a soft, silvery rare-earth metal, most important today for the neodymium-iron-boron magnets, the strongest permanent magnets known, which drive everything from headphones to wind turbines and electric motors.
Beyond its magnets, neodymium tints glass and ceramics a delicate violet and forms the doped crystals and glasses of powerful solid-state lasers used in industry, medicine and research. The powerful neodymium-iron-boron magnet itself was invented independently in 1984 by General Motors researcher John Croat in the United States and by Masato Sagawa at Sumitomo Special Metals in Japan, a near-simultaneous dual discovery that led to years of patent litigation between the two companies before cross-licensing agreements let both continue producing what remains, four decades on, the strongest type of permanent magnet commercially available. These magnets, though barely a few decades old, are now judged essential enough to modern manufacturing that several governments classify neodymium among their most strategically critical minerals.