Uranium

(yoo-ra'ne-um.) [From Gr. ouranos, the heavens.) (Chem.) A metallic element not well known in the pure state. It is hard, and of an iron color, somewhat malleable. Sp. gr. 184; at. weight, 120. Symbol, U. The only compounds which need be mentioned here are uranic oxide (U203), a yellow powder which unites with bases, forming salts called uranates. Uranate of ammonia is of a fine deep yellow color, slightly soluble in water. It is used as a pigment under the name of uranium yellow. Uranate of sodium is a yellow crystalline salt, almost insoluble in water. It is much used for staining gla and porcelain, to which it communicates a beautiful canary color. Gla colored with uranium is very fluorescent. [s. 923]