CARNELIAN, CORNELIAN, a translucent reddish or yellowish-red variety of fine-grained silica (silicon dioxide). It is a sub-variety of chalcedony in which the coloring matter is prob. iron. Sard (sardius, q.v.) is sometimes referred to as being a variety of carnelian, and sardius in KJV (Rev 21:20) is given as CARNELIAN in RSV. Onyx (q.v.), another fine grained variety of silica referred to in KJV (Exod 39:13), is given as CORNELIAN in NEB. Carnelian was one of the most treasured stones of the Romans and the Greeks, and was used esp. for intaglios and signets. Several derivations have been assigned to the word: from carneus (Lat., flesh-colored), from cornu (Lat., horn, due to the horny appearance of some specimens and cornaline (French, a shrub having a red berry). It is formed by deposition from hydrothermal waters of igneous origin or from ground water, with India one of the localities.