A silvery metallic chemical element (symbol Y) with an atomic number of 39, mainly found in combination with lanthanide elements in rare-earth minerals.

plural of yttrium

(physics) An isotope of yttrium, ⁹⁰₃₉Y, that is used in radiotherapy

(mineralogy) A synthetic mineral used for its special magnetic/optical properties

plural of yttrium iron garnet

(chemistry) A birefringent crystal, typically doped with neodymium and used as a gain medium in solid-state lasers.

plural of yttrium lithium fluoride