a species of precious stone, belonging to the siliceous genus. See Mineralogy Index. The ruby is of various colours; as, of a deep red colour inclining a little to purple; the carbuncle of Pliny; the spinel, of the colour of a bright corn poppy flower; the balass or pale red inclining to violet. Tavernier and Dutens inform us, that in the East Indies all coloured gems are named rubies, without regard to what their colours may be; and that the particular colour is added to the name of each in order to distinguish them from one another. The spinel rubies are above half the value of diamonds. of the same weight; the balass is valued at 30 shillings per carat. Tavernier mentions 108 rubies in the throne of the Great Mogul, from 100 to 200 carats, and of a round one almost 24 ounces: there is also mention made by other travellers of rubies exceeding 200 carats in weight. According to Dutens, a perfect ruby, if it weigh more than 34 carats, is of greater value than a diamond of the same weight. If it weigh one carat, it is worth ten guineas; if two carats, 40 guineas; three carats, 150 guineas; if six carats, upwards of 1000 guineas.

Rubies, it is said, are artificially made from Brazilian topazes of a smoky appearance, by giving them a gradual heat in a crucible filled with ashes, until it be red hot.

Rock Ruby, the amethystizontas of the ancients, is found in Syria, Calcutta, Cananor, Cambaya, and Ethiopia. It is the most valued of all the varieties of garnets, and is frequently sold as a ruby under the name of rubinus Russicum.