ruby

A deep red, translucent variety of the mineral corundum, highly valued as a precious stone.

Something, such as a watch bearing, that is made from a ruby.

A dark or deep red to deep purplish red.

Of the color ruby.

In 1887, M. Frémy, with the aid of his preparateur, M. Verneuil, undertook new experiments on the crystallization of alumina, and had the satisfaction of obtaining very beautiful artificial rubies. Now M. Verneuil, today professor at the Museum, has discovered the method of producing the ruby artificially by melting a mixture of alumina and oxide of chrome at a constant temperature of several thousands of degrees, and in layers superposed from the outside to the inside, in order to prevent the production of cracks in the crystalline mass. This eminent chemist has succeeded in creating a magnificent ruby, weighing about 2,500 grams, and having a commercial value of about 3,000 francs. …

The deepest red topaz which owes its color to heating, to the right degree, of the yellow Brazilian topaz. Further heating turns it pink, and still continued heating renders it colorless. See topaz.

The clear rich-red variety of corundum. (See corundum.)

A pure or somewhat crimson red color.

Something resembling a ruby; a blain; a blotch; a carbuncle.

In heraldry, the tincture red or gules, when blazoning is done by means of precious stones. See blazon, n., 2.