Yttrium
n.-
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 number 39. Atomic weight, 88.9.
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.
