Scientific Rubies and Sapphires

The scientific ruby is wholly the result of artificial means but is genuine to the extent of being a properly proportioned combination of the chemical constituents of the natural ruby; in manufacturing the scientific ruby we begin with a solution of common alum, to which a trace of chrome alum is added as the ultimate colouring constituent. Now add ammonia, and there results a gelatinous precipitate of the hydrates of aluminum and chromium. This gelatinous precipitate is filtered off, evaporated down to dryness, and subsequently calcined into an intimate mixture of alumina and the oxide of chromium. It is then ground into an impalpable powder, and placed in the transforming apparatus. Through a tube passes a supply of coal-gas, through another tube a supply of oxygen. The two meet where they are ignited, and constitute a carefully regulated flame whose temperature is practically two thousand degrees. In a box at the top, is placed the powdered alumina, and the bottom of this box consists of a fine sieve. A small automatic tapper carefully jars the powder through the sieve and through a tube, which serves for the supply of oxygen. It thus happens that every trace of the powder must pass through the flames of two thousand degrees.

In a critical review of this process and its results, a very high scientific authority stated that:

These properties agree exactly with those of the natural ruby; but there is one feature by which these stones could be recognised as having been artificially produced; and that is by the form of the cavities existing in them, these being always spherical. The cavities in a natural ruby are always of an irregular form, and this would always afford a means of detecting the artificial stone.

The stones are rubies and are not imitations, as so many of their predecessors have been. But they are not natural rubies, even although produced from clippings of the same, since the crystalline growth is a new one after the clippings have been fused.

The sapphire as well as its sister of the corundum family, the ruby, has for years been the object of solicitude on the part of scientific experimentalists, who would produce real sapphires by artificial means; Mr. A. H. Petereit, of New York City, the well-known dealer in gems and gem minerals, who purveys rarities in this line to collectors the world over, and whose inventive genius is represented by more than twenty-five patents, exhibited to the author a "reconstructed sapphire" which, tested merely by a visual examination, rivalled natural sapphires, that of the same colour and purity would be very costly gems. Mr. Petereit's process is secret, and he modestly claims success only to the degree of producing stones of a size that will cut into small gems. Of the Petereit sapphires The Mineral Collector says:

We are pleased to announce that the honour has fallen to an American to at last manufacture a real reconstructed sapphire; successful in hardness, colour, brilliancy, and transparency. Efforts have been made in France, Germany, and other countries to successfully make blue sapphires, and, although they have been successful up to the cooling point, they always lost their colour and became gray when cool.

Mr. A. H. Petereit has had a German chemist working on a formula of his own for two years past, and has had his efforts at last crowned with success. At a meeting of experts in the gem business the reconstructed sapphires were placed among the real stones and they had to admit they were equal if not superior to the real gems.

When Mr. Petereit took up the mineral business his inventive mind was turned into a new channel, the manufacture of artificial gems. Already stories were being told of great successes accomplished in this line, but when it came to produce the stones they failed in one form or another; either the colour or hardness was wanting.

The new sapphires he has invented are perfect in every way. They cannot be scratched by the natural sapphire, they have a beautiful deep blue colour, their brilliancy is only equalled by the diamond, their specific gravity is exactly the same as the natural stone.

His success with scientific rubies was due to the fact that those he handled were the best in the market. They were made from small natural stones by a secret process and not from aluminum and other chemicals, as many now on the market were.