praseodymium

Praseodymium is a chemical element with the symbol Pr and atomic number 59. It is a member of the lanthanide series and occurs with other rare earths in minerals such as monazite and bastnasite. It is a soft, silvery‑gray metal that tarnishes slowly in air and forms trivalent compounds. The most common oxidation state is +3, with other oxidation states known in certain compounds.

Natural praseodymium has a single stable isotope, 141Pr; numerous radioactive isotopes have been synthesized. Praseodymium was discovered in 1885 by Carl Auer von Welsbach, who separated it from didymium, a historically recognized mixture of lanthanides. The name derives from Greek prasios meaning green and didymos meaning twin, referring to the green color of some Pr3+ salts and its association with didymium.

Sources and production: praseodymium is obtained from monazite and bastnasite ores and is separated from other rare earth elements through solvent extraction and ion-exchange techniques. It is typically produced as a metal by reduction of oxides or halides after purification.

Uses: major applications include as an alloying addition to neodymium-iron-boron magnets to improve high-temperature performance, and as a pigment and colorant in glass and ceramics that yields yellow‑green colors. It is also used in some catalytic and materials‐science contexts and in research on advanced optical and electronic materials.

Safety: as with other rare earths, praseodymium compounds should be handled with care. Inhalation of dust or fumes can be harmful, and appropriate industrial hygiene practices should be followed.