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THE DIAMOND.
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were obtained from inaccessible valleys by throwing pieces of
meat into them for the vultures to seize and bear away, when the gems adhering to the flesh were scattered by these birds of prey, to be gathered by the natives. Properties. — The diamond differs from all other precious
stones in some of its properties, and surpasses them all in others. It holds the highest rank in the scale of hardness; consequently, it can scratch all other minerals and still remain intact from abrasion. Its specific gravity, though not the highest, is remarkably uniform. The lustre is superior to that of any other gem, which,
however, requires artificial methods for its development in the highest degree, though occasionally it has been found with surfaces naturally polished. This lack of brilliancy in its rough state has, undoubtedly, caused it to be overlooked by those seeking for it. The remarkable lustre of the diamond is said to arise from
its reflecting power, by which it throws back all the light which strikes it at an angle exceeding a little more than twentyfour degrees. This gem possesses the property of bending'the rays of light out of their regular course and scattering them ; to these refractive and dispersive powers is due that beautiful play of colors, sometimes called its " fire," which constitutes one of its chief attractions. There is no other gem comparable to the diamond for this interesting phenomenon, and it is even possessed in a greater or less degree by different varieties of this precious stone, the perfectly colorless specimens exhibiting it in the greatest perfection, and the darkest in the least, or not at all. The kind of light by which it is seen has an influence upon the vividness of the prismatic colors, artificial being more favorable for producing the best effect than natural, and the flame of a wax candle superior to the brilliancy of gas. |
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