336 THE DIAMOND AND OTHER PRECIOUS STONES. 



century, ^^ave many years of his life, and out of this study created a 

 new science, one of the titles to glory of the human mind. 



Pythai^oras and Plato had without doubt. given attention to crystal- 

 lography, since in their schools they announced the marvelous propo- 

 sition that nature, in the depths of her recesses, occupies herself with 

 geometrical problems, and that God geometrizes incessantly, 



Aei deog yEC^iierpet. 



The old alchemists contended that the philosopher's stone could be 

 produced from the commonest substance possible, and nature seems to 

 have favored this idea in producing the most costly gems from the most 

 worthless materials. She converts, as we have seen, a small quantity 

 of black and friable carbon into a transparent diamond of a liardness 

 and brilliancy uuequaled. She takes a little of the glazing which the 

 potter uses in his ordinary operations, and, coloring it with a trace of 

 iron, produces a ruby or a sapphire. From a little worthless pebble, with 

 slight additions, she forms the topaz, the emerald, and the amethyst. 

 Some of the last-named gems have been reproduced in the furnaces of 

 Sevres in the same manner, without doubt, as nature has elaborated 

 them, in her vast volcanic workshops, by those mysterious operations 

 ■which have giv.en to Vesuvius the title of the great crystal manufactory. 

 Every one knows of the sarcasm with which Rousseau reproached the 

 chemist Kouelle, demanding of him that he should produce corn from 

 the chemical materials of which it was composed, rather than destroy 

 that already made in its analysis. What would he say if he had seen the 

 chemist produce carbon from the diamond, as readily as from a bit of 

 wood or sugar, while he was powerless from the carbon to create the 

 precious gem ? 



It might seem at first sight that those countries containing diamond 

 mines, or mines of crystallized carbon, were the most favored; but this is 

 far from being the case. The mines of Golconda, and of Visapour in 

 India, of Brazil, of the Ural, and of Borneo, are not Avorth a moiety of 

 those deposits of coal with which nature, a little parsimonious in regard 

 to France, and still more so toward the vast territory of Russia, has 

 endowed Belgium, England, and to an immense extent the United States. 



By way of illustration, we can state that England, with all her wealth, 

 does not import precious stones of a value greater than twelve or thir- 

 teen millions of francs, while her mines of coal yield a value of five hun- 

 dred millions of francs per annum. How precious is this coal! 



The diamond is commonly found imbedded in a sort of reddish cement. 

 Sometimes the rock containing them requires to be broken, and often 

 the sand at the base of torrents, or the earth which has received the 

 waste of diamond-bearing rocks, is gathered, and submitted to frequent 

 washings by machinery, to exclude the gravel and stones i^rior to the 

 hand-washing which secures the gem. 



Diamonds are always found covered by a rough coat, which is, in fact, 

 the i^roduct of the chemical action of the crystalline formation. JS'early 



