YTTRIUMS

Noun

yttriums

plural of yttrium

Source: Wiktionary

YTTRIUM

Yt"tri*um, n. Etym: [NL., from Ytterby, in Sweden. See Erbium.] (Chem.)

Definition: A rare metallic element of the boron-aluminium group, found in gadolinite and other rare minerals, and extracted as a dark gray powder. Symbol Y. Atomic weight, 89. [Written also ittrium.]

Note: Associated with yttrium are certain rare elements, as erbium, ytterbium, samarium, etc., which are separated in a pure state with great difficulty. They are studied by means of their spark or phosphorescent spectra. Yttrium is now regarded as probably not a simple element, but as a mixture of several substances.

Source: Webster’s Unabridged Dictionary 1913 Edition