Gems

Gems, stones of exceptional beauty and value. In archaeology the term is applied to engraved precious stones, used for sealing or as a personal ornament, or applied to decorative purposes. Signet rings became general among the Greeks and Romans, but apparently sealing was not the purpose for which gems were originally worn. The art of gem engraving was carried by the ancients to a degree of perfection which no subsequent efforts have reached. It is doubtful whether it originated in Egypt or Assyria. From the harder quality of the stones used in Egyptian art, it may be inferred that it would more naturally spring up there, but the early use of soft stones and simple instruments points rather to Assyria. The gems of the two peoples have not much in common. The earliest found in Assyria are cylindrical in form, bored through their length to admit a cord, by which they were fastened to the wrist. Babylonian gems resemble the Assyrian, but in Persia, where chalcedony was the favourite material, a conical shape was afterwards substituted, and the design was engraved on the base. The Egyptian gems are mostly scarabs, and the same form predominated among the Etruscans, where the art was in a very flourishing condition in the 3rd century B.C. The first Greek artist whose name is recorded is Theodoras of Samos, who engraved the emerald in the ring of Polycrates; but it is doubtful whether any genuine intaglios now existing can be referred to an earlier period than the Peloponnesian War. Greece afterwards produced many famous engravers, including Pyrgoteles, who was employed by Alexander the Great. Sards, jacinths, and amethysts were the stones most used. The engravings represent mythological and heroical subjects, as well as portraits of deities, kings, and historical characters. The art of engraving in cameo - a species of relief executed in stones consisting of differently coloured layers - seems to have been introduced under Alexander's successors. As the fragments of Alexander's empire were successively conquered by the Romans, they became acquainted with gem-engraving, which was henceforward practised at Rome, reaching its highest development there during the period of the early emperors. Among artists of this age Dioscorides, who lived in the time of Augustus, holds the first place. Pliny gives an exhaustive list of stones used by the Romans. Very hard and valuable stones, such as the diamond, sapphire, and ruby, seem to have been seldom engraved. The sardonyx was especially adapted to cameos, on account of its fourfold variety of colour - blue, black, white, and red. The other stones used included the emerald, sard, beryl, amethyst, onyx, jacinth, topaz, opal, and garnet The engravings on Roman gems resemble the Greek in their general character. After the 2nd century A.D. the art gradually declined, and appears to have been almost, if not completely, lost during the Middle Ages. At the close of the 15th century it was revived by Lorenzo de' Medici, and flourished in Italy for about a hundred years. In the 17th century it was cultivated with much success in Germany and France, and since then there have been many skilful engravers in all the chief countries of Europe. The attempt to manufacture artificial gems, which dates from the discovery of the chemical composition of precious stones, has met with considerable success during recent years.