in natural history, a species of gems, being a beautiful gem of a red colour with an admixture of purple.

This, in its most perfect and best coloured state, is a gem of prodigious beauty and extreme value; it is often found perfectly pure and free from blemishes or foulness, but much more frequently debased greatly in its value by them, especially in the larger specimens. It is of very great hardness, equal to that of the sapphire, and second only to the diamond. It is various in size, but less subject to variations in its shape than most of the other gems. It is usually found very small, its most common size being equal to that of the head of the largest sort of pins; but it is found of four, eight, or ten carats, and sometimes, though very rare, up to twenty, thirty, or forty. It is never found of an angular or crystalliform shape, but always of a pebble-like figure, often roundish, sometimes oblong and much larger at one end than at the other, and in some form resembling a pear, and is usually flatted on one side. It commonly is naturally so bright and pure on the surface, as to need no polishing; and when its figure will admit of being set without cutting, it is often worn in its rough state, and with no other than its native polish.

We have the true ruby only from the East Indies; and the principal mines of it are in the kingdom of Pegu and the island of Ceylon.

heraldry, denotes the red colour wherewith the arms of noblemen are blazoned; being the same which, in the arms of those not noble, is called, gules. See Gules.