Originally A Variegated Onyx Cameo, Or Other Parti-Colored Stone, on which figures and landscapes appeared, and more commonly applied to a gem in different-colored layers, carved in relief with figures contrasting with the color of the background. Varieties of chalcedony, jasper, onyx, sardonyx, and sometimes turquoise, are the most common gems used; but softer and cheaper materials are of late much employed for this purpose. Cameo cutting is an art of remote origin, and the word is of obscure derivation. The art was certainly practised by the Egyptians, and was brought to a high state of perfection by the Greeks; and yet it is probably not so old as the simpler process of carving in intaglio. Besides employing the natural gems, the Romans in the time of Pliny made use of an artificial paste in two colors, called vitrum obsidianum. But the hard stones used by the Greeks, by the delicacy of finish of which they are susceptible, and by the durability of the lines carved upon them, have proved a better material for transmitting to distant ages an idea of the high at- • tainments of this cultivated people in art than either bronze or marble. Even now connoisseurs distinguish between modern gems and those cut more than 2,000 years ago, by the superior polish of the latter.

In the 4th century cameo cutting had fallen into disuse, the art ending, as it began, in lifeless stone. On its revival in Italy, in. the 15th century, gem engraving received especial patronage from Lorenzo and Pietro de' Medici. Specimens of this period rival in perfection those of more ancient times. The art has since continued to be extensively practised in Italy; but its introduction in other parts of Europe hardly extends beyond the present century. The chief peculiarity of the Italian style is the converting of blemishes in the material into points of attraction, and bringing them boldly out in alto rilievo, as if designed for some special representation; while the Greek, seeking perfect harmony in the colors of the gem, by a series of subtle curves and most delicate lines running through its low relief, effectually concealed the labor, made so obvious in the productions of later times. The first cameo of which we have account was the ring of Polycrates, carved by Theodorus of Samos, about 550 B. C. Among the finest cameos are those in the imperial cabinet of St. Petersburg: one of Perseus and Andromeda, on a pale brown sard, the figures of exquisite finish in high relief; the other, known as the Gonzaga cameo, of Ptolemy II. and the first Arsinoe; the same Ptolemy and the second Arsinoe appear on a gem of inferior merit in the Vienna museum.

The latter is rich in cameos, and contains among others an apotheosis of Augustus, wrought on an onyx 8 3/4 inches in diameter, which was purchased by Rudolph II. for 12,000 ducats, and is considered by some the finest cameo in the world. The apotheosis of Augustus and the princes of the house of Tiberius, in the national library at Paris, is the largest and one of the most famous of these works; it is a sardonyx measuring 12 1/2 inches in one direction and 10 1/2 in another, and contains 22 figures. It is often known by the name of agate de la sainte chapelle, from the holy chapel of the palace to which it was consigned by Charles V. It was there regarded as representing the triumph of Joseph under Pharaoh. It came originally from the East in the 13th century. This collection contains many other choice works of this kind, and among the largest and best is one representing Germanicus carried off by an eagle. In the Vatican at Rome are a renowned cameo said to have belonged to the emperor Augustus, and several antique cameos cut in turquoise. At Naples is one ranked among the finest, representing the apotheosis of Ptolemy on one side, and the head of Medusa on the other. In England there are some remarkable cameos, chiefly in private collections.

One of the most celebrated is in the Marlborough collection; it represents the marriage of Cupid and Psyche, and is the work of Tryphon, who is supposed to have lived under the immediate successors of Alexander in Macedonia. Of the ancient cameos, the most noted is the Mantuan vase at Brunswick, representing on one side Ceres seeking her daughter, on the other the goddess teaching agriculture to Triptolemus. - At Yekaterinburg, in the Ural mountains, Atkinson speaks of seeing a workman engaged in cutting a head of Ajax, after the antique, in jasper of two colors, the ground a dark green, and the head a yellowish cream color, in very high relief, and intended for a brooch. It was a splendid production of art, made, however, at a cost for labor of only 3s. 8d. sterling per month, and 36 lbs. of rye flour. In other countries, where this skill commands higher prices, the great expense of cutting these hard substances has led to the substitution of softer materials, and varieties of porcelain and of enamelled glass are now often used. But the material most extensively employed is the shell of various species of mollusca, which, while it is easily carved, presents layers of a fine natural polish and beautiful colors.

The use of shells began in Italy about the year 1820, and for some years the whole consumption was about 300 per annum, all of which were sent from England, and sold for about 30s. sterling each. Since then this art has been conducted with great success in Rome, and to a much greater extent in Paris. In 1847 the consumption had become very large in Paris, so that the sales in that year were reported to amount to no less than 100,500 shells, at an aggregate cost of £8,960, and the value of the cameos was estimated at £40,000. The shells are of four varieties, known as the bull's mouth, black helmet, horned helmet, and queen conch. The queen conch is referred to by Woodward as the cassis Madagascariensis. This and the C. tuberosa he describes as presenting a white upon a dark claret color; the G. cornuta, white on orange ground; the G. rufa, a pale salmon on orange; and strombus gigas, yellow on pink.

The black helmet is probably the G. tuberosa, which presents a white upper layer upon a dark, almost black ground. The horned helmet is no doubt the G. cornuta with a pink ground. The bull's mouth, the under layer of which is red resembling the sardonyx, is probably the strombus gigas. These shells have three layers, the upper and dark-colored serving for the hair, wreaths, armor, etc.; the next, white, for the figure; and the third for the ground. The pieces are cut out of the required size by a metallic blade fed with diamond dust, or emery and water, and are shaped by grinding and whetting. Each piece is then cemented upon a stick, which serves as a handle during the operation of cutting. The design is marked out with a pencil, and then scratched in with a sharp point. The cutting is afterward done with the use of a number of delicate pointed instruments made of steel wire, as also of small files and gravers. Holtzaffpel gives particular directions respecting the process. " The general shape should be first wrought, with care to leave every projection rather in excess, to be gradually reduced as the details and finish of the work are approached.

To render the high parts more distinct during the process of carving, it will be found convenient to mark them slightly with a black-lead pencil. Throughout the cutting great caution should be observed that in removing the white thickness the dark ground is not damaged, as the natural surface of the dark layer is far superior to any that can be given artificially; indeed, should the ground be broken up at one part, it would be requisite from its lamellar structure to remove the entire scale or lamina from the whole surface, a process that will be found very tedious and much more difficult than the separation of the white from the black thickness. In order that the finished cameo may possess a distinct outline at all points of view, it is desirable to adopt the system followed in antique cameos, namely, to leave all the edges of the figure quite square from the ground, and not gradually rounded down to the dark surface. Should the latter method be followed, it will be found that the ouline is in many places undefined, owing to the color of the white raised figure of the cameo gradually merging in that of the dark ground. This evil is entirely avoided by leaving the edges of the figure quite square for the thickness of about 1/50 of an inch.

The surface of the cameo should be finished as nearly as possible with the cutting tools, as all polishing with abrasive powders is liable to remove the sharp angles of the figures, and deteriorate the cameo by leaving the form undefined. When, however, the work has been finished as smooth as possible with the cutting tools, the final polish may be given by a little putty powder used dry upon a moderately stiff tooth brush, applied with care, and rather to the dark ground than to the carved surface; this is the concluding process, after which the cameo is ready for removing from the block prior to mounting." - Cameos carved in onyx and carnelian demand more skill, as well as labor, than those in shell. A drawing is first made on an enlarged scale, and from this a model in wax of the exact size. The outline is then drawn on the stone, and the engraving is executed with the tools used by the lapidary for engraving seals, being drills of soft metal, as copper or iron, made to revolve rapidly, and fed with emery and oil. False cameos are sometimes made by carefully cutting out the engraved portion of antique gems and attaching this to a ground of agate of another color. Beudant refers to some cameos in a slaty kind of onyx, schistes onyx, which are brought from China as objects of curiosity.

They are sheets of rock resembling very compact slates, and presenting three or four differently colored layers; one a brown, which is the ground, others rod, white, and greenish. In these the Chinese have sculptured various objects, as the interiors of houses, and landscapes, which are sometimes enlivened with figures of men and animals. Some are so large that they may be regarded as bass reliefs for interior decorations. - The art of cutting cameos in onyx and sardonyx, which for some years has been comparatively neglected, or has been superseded by the cheaper and more easily wrought shell cameos, has recently been revived in Rome and in Paris, though the best productions of these cities are inferior to the work of ancient and mediaeval artists. In England the art has never been sufficiently encouraged to induce many artists to pursue it exclusively, though the work of some of the London gem engravers bears a high reputation. Paris is now the chief centre of cameo cutting, and there are to be found the best artists,designs, and facilities for the work.

The Franco-German war of 1870 drove out many of these artists, five or six of whom emigrated to New York, where cameo cutting has been carried on to a limited extent for several years, and where there are a few artists who execute in shell portraits and other designs for rings and brooches which are creditable as works of art. But cameo cutting, as a successful business in the United States, is only beginning to exist, and that almost exclusively in New York. A single jewelry house in that city had orders in 1872 for 5,000 cameos, such as ring stones worth from $2 to $50 each, and brooches from $20 to $250 each; and all these orders were executed in Paris, excepting perhaps 50 stones, and these mainly to complete imported sets, which were cut in New York.