Defn: 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.
YTTRO-CERITE
Yt`tro-ce"rite, n. (Min.)
Defn: A mineral of a violet-blue color, inclining to gray and white.
It is a hydrous fluoride of cerium, yttrium, and calcium.
YTTRO-COLUMBITE; YTTRO-TANTALITE
Yt`tro-co*lum"bite, Yt`tro-tan"ta*lite, n. (Min.)
Defn: A tantalate of uranium, yttrium, and calcium, of a brown or black color.
YU
Yu, n. Etym: [Chin.] (Min.)
Defn: Jade.
YUCCA
Yuc"ca, n. (Zoöl.)
Defn: See Flicker, n., 2.