Dysprosium – 66
Dysprosium is a heavy rare earth element that is relatively scarce and highly valuable. It is found in lower concentration in monazite, bastnasite, xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine.
Manufacture of Terfenol-D (military naval sonar systems). Doping magnets for regenerative braking systems and motors in hybrid cars (retain magnetic properties in high-temperature situations). Used for lasers and nuclear reactors. Phosphor coating for compact fluorescent lamps (CFL). Glass polishing for cathode ray tubes (CRT), plasma (PDP), and liquid crystal (LCD) screens. Used to make strong magnets for microphones, speakers, hard drives, wind turbines, and hydro power turbines.