Despretz’s experiments, which were based upon certain combinations of carbon, are deserving of mention. The chemists have discovered that in combining sulphur and carbon a colorless liquid is produced resembling water, and apparently containing nothing but sulphur and carbon. Therefore, Despretz reasoned, if he could get rid of the sulphur by some manner, the carbon might be crystallized. And to obtain this result, the action of the volcanic battery offered the most plausible means. With the aid of this battery the experimenter really succeeded in obtaining on a thread of platina, passed through a solution containing carbon, some small crystalline depositions, which by their form and hardness seemed to be embryonic diamonds. But here the experiment ended. Nature refused to reveal her secrets.
The alchemists of the Middle Ages seeking the transformation of gold from baser metals, have been well represented by the chemists of the present century attempting to imitate the diamond. Philosophy and science have united their efforts in these fascinating experiments; but Nature still defies the most determined efforts of art in respect to the reproduction of the diamond.
The mineral appears to be an allotropic form of a simple elementary body which Nature offers to us with lavish hand. And when we consider the triumphs of chemistry, the process of transforming this element into the coveted form does not seem to be so very difficult to the casual thinker. But Nature is stubborn in revealing her simple acts. However, we are not without faith in these determined efforts of scientific skill; for we know that art now produces the brother of the diamond, graphite, at will. And we see that at the soda works at Aussig this form of carbon is obtained as a secondary product by the decomposition of cyanogen and its combinations. We do not, however, look forward with much pleasure to the realization of this idea; for success in producing the diamond will annihilate at a single blow an important article of commerce, and rob ornamentation and investment of one of its most desired objects.
Art, however, in its researches on this subject, has succeeded in producing a glass which, when cut, approaches very closely the brilliancy and prismatic display of the diamond. The artificial gems made from this glass, which is supposed to have thallium as a base, instead of lead, are really superior examples of art. “Nothing but glass,” is a phrase too often used contemptuously and unjustly; for these imitations are quite as charming as the adamas itself. In the flash of their rainbow hues, they surpass some of the great diamonds, like the Koh-i-noor; and in brilliancy they exceed all other gems. Their refraction reaches 2 on the established scale, while that of the diamond is reckoned at 2.4, and that of the sapphire, 1.79. They lack, however, hardness; and the effect of time dims their lustre. But this defect may yet be remedied; for the ancients made glass quite as hard as quartz. And when we come to examine those wonderful specimens of ancient glass, with their exquisite colorings, exhumed by General Di Cesnola in the Phœnician tombs of Cyprus, who will venture to establish a limit to the art of glass-making? Even within the past few years, a process has been discovered by which the elasticity and hardness of glass have been increased to a remarkable degree; and if the defect of brittleness can be overcome, a new era in glass-making will have been reached.
Artificial diamonds are often worn at the present day; and the fair wearer consoles herself with the hope that, when sunnier days come, the artificial will give place to the real. It will not be soon forgotten by the votaries of fashion, that the Duchesse de Berri, arriving in France, received for her bridal ornaments only the imitation, and that she wore them.
CHAPTER XIV.
VALUE OF THE DIAMOND.
The history of the commercial value of the diamond, extending back to a distant period of time, forms an interesting chapter for the philosopher as well as the merchant. It would appear that the gem had been comparatively independent of the caprice of fashion, and that it has had for many years a value quite as fixed as gold or silver. This comparative valuation only applies to the snow-white diamonds, and to those whose imperfections are not readily discernible to the naked eye.
In estimating the value of diamonds, Barbot divides their shades into fifteen degrees, as follows: In the first degree he places the rare diamonds which exhibit the vivid gleam like the flash of polished steel; second degree, snow-white, first water; third degree, white, first water; fourth degree, white, with faint shades, red, yellow, and blue; fifth degree, white, yellow, or green, second water; sixth degree, grayish-yellow or green, second water; seventh degree, orange yellow; eighth degree, translucent topaz yellow; ninth degree, translucent deep green; tenth degree, translucent brick-red; eleventh degree, translucent deep red; twelfth degree, quite opaque, dingy blue; thirteenth degree, quite opaque, deep bottle green; fourteenth degree, quite opaque, brown or blackish; fifteenth degree, quite opaque, black as jet.
In ancient times, the gem probably had no fixed commercial value, and was sought for as a curiosity or as a talisman. In the fifteenth and sixteenth centuries, the goldsmiths of Italy, which was then the richest country in the world, established a comparative valuation for the four precious stones, ruby, emerald, diamond, and sapphire. From these accounts we learn that the diamond of one karat was valued at 100 gold scudi, and that the emerald was estimated at 400, and the red sapphire, or ruby, at 800, or eight times the price of the adamas. These valuations, if we estimate the scudi at nine English shillings, make a diamond of one karat worth $225, and the ruby of the same weight at $1,800, or nearly two thousand dollars, a statement which is quite incredible.
In the sixteenth and seventeenth centuries and even before these dates, Venice was the chief gem mart of Europe. Her merchants had control of a great part of the trade with the Eastern countries; and most of the Oriental luxuries passed through their hands. From the account of the auction sale, in the year 1606, of the effects of a diamond merchant in that city, we learn the value of diamonds of one karat weight at that time. They were then valued at £21 13s. 4d., which was an enormous sum, compared with the value of money at the present day.