Gems Made by Science

Far different from the imitation of gems is the making of them by artificial means, with the result of a real gem that is but slightly distinguished from those produced in Nature's laboratory. Although there are distinctions discernible to the expert with the aid of the magnifying glass, the gem stones thus produced-that are worthy of notice-contain the same component parts in their proportions that the natural stones do, and equal them in the principal characteristics of hardness, specific gravity, and refractiveness.

To quote Wirt Tassin:

A sharp distinction is to be drawn between the imitation of a gem stone and its formation by artificial methods. The imitation gem only simulates the natural substance; the artificial gem is identical with it in all its chemical and physical properties. Until recently the laboratory gem was hardly more than a curiosity, although its synthesis has undoubtedly been of value from the theoretical standpoint. Examples of this class are to be found in the diamond as produced by Moissan in the electric furnace and the synthesis of spinel and chrysoberyl by Ebelmen from mixtures of alumina and glucina, respectively, using boric acid at very high temperature as a solvent. Hydrofluoric acid and silicon fluoride have also been used to induce combination between silica and other oxides. In this manner topaz, a complex fluo-silicate, has been made by the action of fluoride of silicon upon alumina.

The minerals thus formed have usually been very small and of no commercial value. Quite recently, however, rubies have been produced by the fusion of alumina with a trace of chromium oxide in the electric furnace, and the art has progressed to such an extent that the product is now on the market for sale as watch jewels. The electric furnace has also produced another product which, while strictly speaking not a synthetic gem, yet is essentially an artificial one. Imperfect rubies, chips, and small stones, are fused in the furnace together with the addition of a small amount of colouring oxide such as chromium. The fused product is then cut and polished, and the result is a ruby of good colour and of fairly large size. Emeralds and other coloured stones have been made in the same way, and so promising has the industry become that the courts have been called upon to decide what constitutes a ruby. Their decision was in substance that the word ruby could be legally applied only to the red-coloured corundum, anhydrous oxide of aluminum, occurring ready formed in nature.

Reconstructed rubies however are in the main rightly placed and justly valued, for they are generally used in large quantities for medium-priced jewelry.

The French chemists Fremy and Verneuil have succeeded in manufacturing true gems, rubies chiefly, but also sapphires, by artificial processes. A title given to gems created by this or similar processes by man is "scientific" ruby, emerald, sapphire, or whatever the gem may be. Mr. Rudolph Oblatt of New York is an American producer of the "reconstructed" ruby, which has attained some commercial success, and its effect upon the market for rubies, whether this be considered desirable or otherwise, has been to lower the price of natural rubies because the demand has been lessened for them; this applying probably only to stones of one carat or less. When "reconstructed rubies" were first offered to the jewelry trade in Paris, and subsequently in the United States, their makers encountered many disheartening rebuffs; to-day many merchants and manufacturers who at first were horrified by, and who resented the suggestion of using the "reconstructed ruby," are complacently handling them in a continually increasing market for medium grade jewelry.

Mr. Oblatt describes his process as follows:

From the small genuine particles of ruby or "ruby sand" found with the real rubies in Burma I select pieces that are alike in colour and qualities; one of these chips I place upon the top of a "U"-shaped platinum iridium tube. Upon this is focussed the heat from two jets of oxygen and hydrogen gas—for the latter can usually be substituted gas from the street mains, as it contains a sufficient proportion of hydrogen gas to qualify it for this use—with a pressure of eight hundred pounds to the inch, producing a temperature of six thousand degrees F. As soon as the first chip is melted I introduce into the flame at the end of an iridium holder a second chip, which when it melts flies off and adheres to the first melted chip and they are fused together. The continuation of this process of adding particles results in the production of a genuine ruby of the shape of a pear, resting on its stem—the first chips fused—varying from five to ten carats in weight. The operation lasts from one to two hours, according to the size of the stone produced. The most difficult part of the process is the cooling; Nature's laboratory in which the ruby was produced had the resources of a tremendous sustained heat and a cooling process of unknown duration. In general, Nature's cooling process was too rapid, the evidence being in the minute cracks, called ribbons, which run through most rubies and the absence of which makes the perfect ruby one of the rarest and costliest of stones, especially when the cut gem weighs two carats or more. The cooling process is secret and one of the most important factors in the achievement of the reconstructed ruby. The enlarged ruby is then cut by the lapidary exactly as is the natural ruby, for it is the same in its chemical and physical constitution. This is attested by analysis made by very high scientific authorities, their reports being in my possession and open to the inspection of anyone.