Among the gems preserved in the museum of the Vatican may be seen two engraved intaglios of early date, upon sapphires of an amethystine hue. Among the most beautiful of the engraved sapphires that have been preserved to us from ancient times is that of Cneus, now placed in the cabinet of the Strozzi, in Italy, which represents the figure of young Hercules. In the collection of gems at Turin there is a white sapphire, on which a fine head of Tiberius has been engraved. There may be seen among the crown jewels of Russia a beautiful sapphire of two shades, engraved with a representation of a female figure enveloped in drapery. The figure is engraved in the darker shade of the stone, while the drapery is carved from the lighter part. The French cabinet boasts of a very fine blue sapphire with an engraving representing the Emperor Pertinax.
King, the excellent and tireless antiquary, mentions, in his chapter on the hyacinthus, several beautiful and unique engraved sapphires. He states that engraved gems of this class, dating to times previous to the Imperial epoch, are extremely rare; still, there are extant some undoubted specimens, among which are a small Etruscan scarabeus and a magnificent head of Jupiter, executed in the purest Greek style. The accidental discovery of the last indicates how many more of the fine gems of antiquity may yet appear in course of time to gladden the lovers of the glyptic art. This gem was an inch in diameter, and of fine color; but to utilize it to the wants of the Turkish possessor, who wished to set it in the handle of his dagger, the engraved side was set downward and thus preserved from injury, while the back of the stone was rudely faceted by some Eastern lapidary. A Medusa’s head of the same style of execution, upon a stone of remarkable beauty, is one of the chief glories of the celebrated Marlborough collection. In the same museum there is another larger and deeper-hued sapphire bearing the head of Caracalla, the short, curly hair of the irascible tyrant being represented by a series of minute holes closely drilled together. One of the most famous of all engraved gems of this material is the signet ring of Constantius. The stone is one of great beauty and perfection, and weighs fifty-three karats. Its engraving represents the Emperor as spearing a monstrous wild boar before a reclining female figure, personifying Cæsarea of Cappadocia, the scene of exploit. It bears an inscription in proof of its royal use,—the letters “Constantivs Avg.” King mentions another fine specimen of the time of Hadrian, representing “Hebe feeding the eagle.” It was heart-shaped in form, of fine color, and quite an inch and a half in diameter.
The museums of Europe contain many examples of mediæval and modern engraved sapphires, one of the finest of which is the famous portrait of Pope Paul III. among the Pulsky gems, and attributed to Il Greco. It is a very beautiful stone, and three quarters of an inch square. In the Marlborough cabinet there is an extraordinary specimen of a thumb ring of high antiquity, cut from a single stone, but of rather a pale tint. Rings containing both plain and engraved sapphires have been the appointed symbol of church authority from a very early day. They have often been bestowed as the badge of pontifical rank, and the custom has descended to the present day. King devotes an interesting chapter to the history and description of this class of ornaments and symbols; and to his pages we must refer the interested reader.
Engraved red sapphires of ancient date are extremely rare, so rare that the experienced antiquaries, Lessing and Clarac, deny the existence of any antique intaglios of this variety. Investigation has proved that many of the supposed engraved rubies are really red spinel, garnet, or zircon. Nevertheless, there are a few examples to prove that the ancients did make use of the gem in the glyptic art, although the act was regarded as one of extreme extravagance, from the rarity, costliness, and beauty of the material. The Devonshire parure exhibits a convex red sapphire of about three karats weight, of pure pigeons’-blood tint, and engraved with a Venus Victrix in the latest Roman manner. Another shows a full-length figure of Osiris, in half-relief, of the time of Hadrian. In the museum of the Jardin des Plantes there are said to be two engraved red sapphires.
There are but few gems with which the blue sapphire can be confounded. The blue diamond can be easily detected by its superior brilliancy and hardness. It is very rare that the tourmaline appears of a deep blue, and still more rare for the topaz to assume the appearance except of the very light varieties, and the same may be said of the beryl. The iolite, which, however, is a very rare mineral, may resemble the blue sapphire, but its inevitable dichroism betrays its character. Turn the gem before the eye, and the deception vanishes; the blue disappears as if by magic, and the stone is gray. Kyanite sometimes appears of the most beautiful blue tints, but its softness indicates its nature, and prevents its use as a gem. The glass-workers, however, produce the most beautiful and attractive imitations of sapphire, and of all colors, lacking but one desideratum, and that is the thus far unattainable degree of hardness. The red, green, yellow, and white varieties may all of them be closely approached in color by other gems, and the best methods of detection are the tests of specific gravity, degree of hardness, and the optical phenomena.
The blue variety of sapphire being less sought after in ornamentation than the diamond, has not had a fixed scale in valuation. Still, prior, or for a few years prior, to 1850, the ordinary sapphire was placed by jewellers upon the same valuation as the emerald, or at about $15 the karat. Since this period its value has quadrupled, but has not kept pace with that of the emerald. The pale-blue stones have only a nominal value, and the same may be said of the very dark blue. But those sapphires which exhibit the perfect tint of the prismatic blue can command very high prices.
The ancient Romans excelled in their imitations of the ruby, both in hardness, color, and lustre; and a number of examples are yet preserved in some of the European cabinets. The bold robber, Charles, the Duke of Burgundy, was the possessor of several famous gems which he carried with him on his campaigns, and used as personal decorations on particular occasions. One of the choicest of them was a monster ruby more than an inch in diameter, which the famous Margaret of Anjou had given him. On that fatal day at Grandson it was placed with the historic diamond in a golden box, and left in the tent of the Duke, where it was captured by the mountaineers. The gems were carried to Berne by the victorious Swiss, and afterwards offered for sale to the rich Nuremberger, Jacob Fugger. Then it was discovered by the expert that the ruby was indeed a lump of red glass of ancient make, and probably of the date of the Roman Empire.
As the red sapphire is one of the rarest as well as the most beautiful of all gems, its value is in keeping with its attributes. As it overpowers all other gems with its gorgeous red, which is a pure prismatic hue, so it transcends all others in price. There are but very few gems with which it can be confounded in color. But no matter what the material may be, provided it displays the royal tint. It is extremely rare that the red tourmaline or spinel exhibit the perfect tint which is the characteristic of the red sapphire. The zircon sometimes displays a fine red color, and may imitate the sapphire. It is also within the range of possibilities that the diamond and garnet may closely resemble the true ruby. We have seen small garnets that exhibited the pigeons’-blood tint. The scarcity of the ruby is so great that fine gems are only to be acquired by the very wealthy. In the times of Cellini, three centuries ago, the price of the red sapphire was eight times that of the diamond. And to-day we may safely adopt Cellini’s estimate, for the gem is so rare that we cannot readily compute its value in comparison with the diamond, which is so abundant.
King, in commenting upon the valuation of precious stones during the past three hundred years, mentions two fine rubies which were sold in London recently for enormous sums of money. One of three karats brought $1,500; while another of finer tint, of less than four karats (11 grains), was sold for $5,500, or for $500 a grain, which price is quite equal to Cellini’s estimate made in the year 1560.