ART. IV.-COMMERCIAL VALUE OF GEMS.

It is an ancient principle of political economy, that in all merchantable articles there are two kinds of value, that of use and exchange. The former applies to the value which is derived from the actual use of the thing, independent of its price in market, and the latter is the value which it will command in exchange for other things, be they goods or money. Thus iron possesses a great intrinsic value in use, from the various uses to which it may be applied for the convenience or comfort of men, and considering its bulk, but a very small value in exchange. On the other hand, there are many articles which possess but a small value in use, but which, from their scarcity or beauty, possess a great value in exchange. Among the most prominent of these articles, are included the various species of gems. These beautiful forms of matter, from their peculiar qualities, brilliancy, color, or scarcity, being used in foreign countries as badges of rank and wealth, and everywhere the object of admiration, and the signs of luxury, are connected with some of the most gorgeous associations of regal pomp and refinement. Being so precious in themselves because so rare, they are the visible emblems with which rank and power delight to dazzle the eyes of the multitude. Hence it is that in monarchical governments we find that the most favorite subjects of display are the jewels of the throne; for it is their great cost which evinces the enormous wealth of these governments. How many thousand acres of our new land would be required to purchase the regal jewels which now blaze within the walls of the Tower of London, or the gems which sparkle on the columns of St. Peter's, at Rome, that once adorned the famous coat of Prince Esterhazy, or the brilliants which sparkle in the regalia of an eastern princess! The great exchangeable value of gems therefore causes the eagerness with which they are sought, inducing the labor of hundreds of men in diving into the ocean for pearls, and in digging into the depths, and washing the sands of the mountains. We propose to devote a brief space to the consideration of the principal jewels now in use, and their commercial value.

As articles of exchange, gems form an important part of the objects of trade. The cases of our jewellers are filled with gems of various sorts, and there is scarcely an individual in the community who has not a portion in his or her possession. With the advance of opulence in this country they now constitute a much-prized part of personal adornment, and are used in numerous forms as implements of luxury, although varying largely, of course, in factitious value and their intrinsic beauty. Poetry has derived some of its most brilliant conceptions from the various splendor of precious stones, and it is well known that these form an important part of our descriptions of that future world which is to be the reward of the good. Of heaven it is declared, "the building of the wall of it was of jasper, and the city was pure gold, like unto clear glass. And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper, the second sapphire, the third a chalcedony, the fourth an emerald, the fifth sardonyx, the sixth sardius, the seventh a chrysolite, the eighth beryl, the ninth a topaz, the tenth a chrysoprasus, the eleventh a jacinth, the twelfth an amethyst. And the twelve gates were twelve pearls; every several gate was of one pearl, and the street of the city was pure gold, as it were transparent glass."

We have no distinct account of the early history of gems. In the scriptures we read of the gem that the high priest wore upon his golden scarf, and the gems set in gold plate called the urim and thummim, each of which represented a tribe. Nor do the ancient writers, when they allude to precious stones, afford us any distinct description by which we can identify their precise character. In the works of Homer, there is no allusion made to precious stones, and Theophrastus and Pliny have mingled their accounts with so much fable as to leave us entirely in the dark respecting their dif ferent kinds and value. A sort of superstition appears formerly to have been connected with the idea of jewels, which with certain foreign people has descended to our own day. Among the eastern nations, the ruby is deemed a talisman, while the Chinese regard it a proper token of friendship. The emerald is a deity of the Peruvians; and he who is conversant with our western savages, well knows that they look upon the places which are supposed to abound in precious metals as endowed with a supernatural influence. Indeed there is ample evidence of the superstition with which these precious articles of traffic were regarded as late as the middle ages, in the work of Marbodus, Bishop of Rennes, whose design is to show the miraculous power of gems. The brightness of the diamond and the various colors of the several gems early attracted the attention of men, and they devoted great care to the polishing of gems, and were accustomed to sculpture upon the softer kinds, figures of their deities, historical scenes, and the heads of distinguished men. During that early period, the art of sculpturing the diamond and the other hard jewels, it appears, was not understood, and that work was performed only upon stones, such as the onyx, carnelian, and jasper, which would more easily yield to the graver. These softer stones were polished by means of a powder prepared from the harder gems, and a smooth surface being obtained, the engraving was performed by iron tools, sometimes pointed with diamond splinters. The art of engraving the diamond was first discovered about the year 1500, by Ambrosius Caradossa, who prepared for Pope Julian II. the figure of a patriarch. But although the ancients did not possess the art of engraving gems in that perfection to which it has arrived at a later period, still we have from the authority of historical accounts, sufficient evidence to convince us that it had arrived to considerable excellence even in that day. The gems which were used by the high priest in the scriptures, were engraven with the names of the twelve tribes of Israel. Who has not heard of the seal of Solomon, or of that which was presented by Alexander to Perdicas, or of the Sphinx which was engraven upon that of Augustus? The engraving upon gems, performed by the Persians and the Indians, was confined to the carving of mythological animals; and the Egyptians sculptured upon their jewels the figures of beetles, which they worshipped, while the Greeks practised the sculpturing of gems in the form of fantastical animals, illustrated with the Greek word "Abraxes."

The art of sculpturing gems was transmitted from the Egyptians to the Phenicians, Hetrurians, and Greeks, and thence it descended to the Romans, with whom it was lost on the decline of the Roman empire in the fifteenth century, during the period of Popes Martin V., and Paul II., when it was finally revived by some fugitive Greeks in Italy. Great credit is due to the Medicians for the revival of the art, and Giovani was deemed the most distinguished gem sculptor of that age. To this period may be traced the origin of the talisman, so distinguished in oriental romance, and

which consisted of carved gems that bore upon their surface Arabian letters. The extreme beauty of the cameos which are dug from the ancient ruins of the old world, have received the marked attention of all lovers of art in our own day. In these works we find all the contrast of light and shade in hair and dress, carved from the different layers of the stone. There seenis to have been, indeed, a beautiful consistency in the gem sculpture of ancient times, which ran through all their works connected with the fine arts. Even the color of the stone determined the mythological device which was carved upon its surface. Thus Bacchus was engraved upon amethyst, as it was the color of wine, and he the god of that subtle fluid. Neptune, the god of the seas, naiads, and fish, floated upon a surface of aquamarine, this gem being like the water in color. Traces of sculpture in gems are found in Germany as early as the fourteenth and sixteenth centuries, and England and France have been distinguished in the same art. We do not design, however, to enter into a particular account of the progress of the art, but to sketch the prominent existing facts connected with the subject of gems, which are most interesting and important at the present day.

The great value of many species of gems, and the frequent opportunities of fraud which occur from their sale, would seem to render a knowledge of their character of great utility to those who have occasion to deal in them, either as a matter of taste or in business. This value is dependent, in great measure, upon their size, form, and quality; and the art of imitating them is so far advanced, and the eye is so frequently deceived in their appearance, that an intimate knowledge of their essential character is absolutely necessary, in order to prevent deception. Thus the use of foil to increase the brilliancy, and the several arts, which are known only to lapidaries, to produce an increased beauty to those which are genuine, as well as to manufacture the spurious, furnish large room for fraud and deception in their commerce. It is well known that in Europe gems are extensively used for the engraving of the armorial bearings of noble families; and the practice, so extensive in England, has been introduced to a considerable degree into our own country. If this custom is valuable at all, it has found in the material of gems a substance most appropriate for that object, not only in beauty and value, but in permanence. The individual who wishes to hand down to posterity the glory of his ancestors, may wear upon his little finger a jewel whose value would purchase a barony, inscribed with the emblems of his ancestral renown, which will blaze and sparkle, when himself and unnumbered generations of his posterity shall have been mingled with the dust.

The engraving, sawing, drilling, grinding, polishing, raising the brilliancy, and the setting of gems, form no small part of the labor connected with this trade. The engraving of diamonds is sometimes performed with an instrument similar to the glass cutters with which we are so familiar, but of a harder kind, and diamond splinters are frequently used for the same pur. pose. After the surface has been rubbed with emory, glass, or leaden wheels, the design is etched with a brass pen, and then engraven with the cutter. Upon hard stones diamond powder is often used, and upon soft ones emory and oil, while the graver is worked by a small iron wheel set in motion by the foot. For the drilling of gems a diamond set in steel is oftentimes required, which works with a bow; and for polishing the diamond, powder and emory are chiefly used. To heighten the color or

brilliancy of gems different species of foil are employed, which tend to reflect a deeper light through the surface, but the most valuable require no extrinsic aid to increase the beauty of their appearance.

It is said that the various colors may be found in the greatest perfection in the different species of the precious stones. The pure and starry brilliancy of the diamond, the deep red of the ruby, the grass-green of the emerald, the violet of the amethyst, the yellow of the topaz, the blue of the sapphire, and the moonlight beauty of the opal, exhibit these various colors in their most perfect lights and shades. These are so numerous that we here give the names of the several species of gems with their different colors.*

Limpid gems.-Zircon, sapphire, diamond, topaz, (pebble) rock crystal, (false diamonds, lake George, Trenton Falls,) beryl, aquamarine.

Red gems.-Zircon, hyacinth, garnet, (oriental garnet) sapphire, ruby, garnet, Bohemian garnet. Pyrope, spinelle, ruby spinelle, ruby balaise, dia. mond, essonite, topaz, Brazilian topaz, (often burnt) tourmaline, siberite, rubellite, rose quartz. Bohemian ruby, carnelian.

Yellow gems-Zircon, sapphire. Oriental topaz, chrysoberyl, topaz. Brazilian, Saxonian, and Syrian topaz, diamond, beryl, rock crystal, citron, fire-opal.

Green gems. Zircon, sapphire, oriental chrystolite, emerald, malachite, chrysoberyl, spinelle, diamond, topaz, aquamarine, chrysolite, idocrase, tourmaline, (Brazilian and Maine,) emerald, beryl, prase, heliotrope, chrysoprase, felspar, Amazon stone.

Blue gems. Sapphire, disthene, (kyanite) spinelle, diamond, topaz, Brazilian topaz, tourmaline, indigolite, turquoise, beryl, aquamarine, dichroite, (iolite) hauyne, lazulite.

Violet gems.-Garnet, sapphire, oriental amethyst, spinelle, axinite, tourmaline, amethyst.

Brown gems.-Zircon, garnet, essonite, diamond, tourmaline, smoky quartz.

Black gems. Diamond, tourmaline, rock crystal, morion, obsidian, pitch coal, cannell coal.

Gems distinguished for their various shadings of color and light.-Garnet, sapphire, star sapphire, chrysoberyl, hypersthene, Labrador spar, dichroite, cat's-eye, adularia, felspar, precious opal, hydrophane.

The diamond being the most brilliant and distinguished species of gem, we shall first consider its character. Among the ancients this gem was very highly prized, and although frequently worn in a rough state, many medicinal properties were ascribed to it, as it was deemed an effective antidote against mania and poison. The art of cutting the diamond with its own powder was first discovered in 1746, by Lewis Van Berghen. The first shape in which it was cut was the table form, with only one row of facets upon the border; but in 1520, the rhomb cut was introduced; and it was

* We would here remark that we are indebted to the valuable work of Dr. Lewis Feuchtwanger for the prominent facts connected with this subject. We learn from him that a new and enlarged edition of that volume may be expected, if sufficient encouragement be given to the present work. Should that volume ever see the light, would it not be well to illustrate it with colored plates of the gems, similar to those which are contained in the treatise of Mr. Mawl on diamonds and precious stones, which was printed in London, in 1813?

not until the reign of Louis XII. that the mode of cutting the diamond into brilliants was invented. The Cardinal Mazarin employed the lapidaries of his time in cutting the diamond into that form, and a number were in his possession which are now owned by the crown of France. It was reserved for the genius of Sir Isaac Newton to discover first that the diamond was combustible; and he drew this inference from the fact of its great refraction of light. That discovery led to a series of experiments that demonstrated its substance to be pure carbon. In 1694, the first experiment was made to discover that fact in Florence, and the members of the academy in the latter city succeeded in volatilizing it with the focus of a mirror. A series of experiments soon followed, which were directed to the composition of this gem from the substance containing carbon; and Dr. Hare, of Philadelphia, succeeded in melting down mahogany charcoal, by his deflagrator, into a form which appeared to possess a sort of metallic brilliancy. Professor Silliman, of Yale College, also tried several experiments directed to the same object, and produced from plumbago small globules, some of which could scarcely be distinguished from the real diamond. Yet all the experiments to compose this hardest of substances by artificial means, have hitherto proved ineffectual.

Diamond mines are found in the East Indies, in the mountain chains of Hindostan, at Roalcorda, near the junction of the Birmah and Ristna; Golconda; and at Visapur and Hydrabad, upon the island of Borneo. In Brazil diamonds were first discovered as late as 1728, having been thrown aside with the rubbish collected from the washings of gold, until an individual, having knowledge of their value, collected a large number and carried them to Portugal, by which he realized a splendid fortune. This fact having however been ascertained by the government, it was ordained, in 1730, that all the diamonds collected in that region were thenceforward the property of the crown. In Russia, the first diamond was discovered in 1829, by Humboldt and Rose, while on their journey to Siberia, upon the west side of the Uralian mountains.

Many of the diamond mines in the East Indies have been relinquished since the discovery of those gems in Brazil. Sumbhulpore, and the neighboring region, is the most valuable diamond district in that country, and they are collected in large numbers by two tribes, called the Thata and Tora, who occupy sixteen villages, and employ their time in searching for diamonds along the beds of the streams, and among all the excavations and alluvial deposits. Their implements are few, consisting only of a pickaxe, a species of shovel, and a board upon which the earth is collected, and a stream of water being let through it, the larger stones are thrown off, and the diamonds picked out. Another mode of searching for diamonds in that country is to surround a tract of land with a wall, to throw in dirt, and by letting in a stream of water for the purpose of washing away the small sands. The gems, if there are any, then appear. The operations of the diamond washers in Brazil are peculiarly interesting. The water is drawn off from the beds of the rivers, and the sediment is left, composed in part of sand and quartz pebbles. A large bench of triangular form is used, in the middle of which is a gutter that is connected with a trough, through which the water runs. The negroes are employed in collecting these gerns, and when one is found, he makes it known by the clapping of his hands. The gem is afterwards delivered to the overseer, who is seated upon an eminence in order to overlook the workmen, and deposits it in a dish of