Short answers, pulled from the story.
Praseodymium is a chemical element with the symbol Pr and atomic number 59. It is the third member of the lanthanide series and one of the rare-earth metals, appearing as a soft, silvery, malleable and ductile metal.
Carl Auer von Welsbach, an Austrian chemist, separated didymium into praseodymium and neodymium in 1885. The didymium mixture had earlier been isolated by Carl Gustaf Mosander, and its composite nature was suggested by Bohuslav Brauner in 1882.
The name praseodymium comes from the Ancient Greek prasinos, meaning leek-green, and didymos, meaning twin. The leek-green colour describes the element's salts, and the twin refers to its origin within didymium.
Praseodymium makes up about 9.1 parts per million of the Earth's crust, an abundance similar to that of boron. It is the sixth-most abundant rare-earth element and the fourth-most abundant lanthanide.
Praseodymium is used with neodymium in high-power permanent magnets for electric vehicles and wind turbines, as a yellow-orange Praseodymium Yellow ceramic stain, in lasers and phosphors, and in didymium glass for welder's and glass blower's goggles. The PrNi5 intermetallic has let scientists approach within one thousandth of a degree of absolute zero.
Praseodymium is extracted alongside other light rare earths, especially neodymium, from bastnasite and monazite ores rather than mined alone. Worldwide production rose from about 2,000 tonnes in 2020 to roughly 3,700 tonnes in 2022, with China producing more than 80 percent of global output, followed by the United States and Australia.
Praseodymium most readily forms the +3 oxidation state, the only stable state in aqueous solution. The +4 state appears in some solid compounds, and uniquely among the lanthanides the +5 state is attainable at low temperatures, observed by matrix isolation in 2016 and in the bulk state in 2025.