Yttrium
in chemistry, a dyad earth-metal, symbol Y, at. wt. 89, exerbium, as a siliisting, together with erbium, as a silicate in gadolinite. It is obtained in the metallic state by digesting the mineral with hydrochloric acid, precipitating with oxalic acid, dissolving the oxalates formed in nitric acid, and separating by a series of fractional crystallizations; the erbium salt, being the less soluble of the two, crystallizing out first. On converting the nitrate into a chloride, and igniting with potassium, the metal is obtained as a blackish-gray powder, consisting of small, metallic, lustrous scales. It unites directly, at high temperatures, with chlorine, oxygen, and sulphur, and probably with other metalloids.