Page:Popular Science Monthly Volume 8.djvu/223

Rh invented in Paris, under the auspices of Cardinal Mazarin; but Tavernier describes the diamonds of Aurungzebe as being of the rose-cut. Therefore, we must give a more ancient date to the pattern than Mazarin's day. The form of the rose-cut is simply that of a hemisphere, covered with small facets. Its flattened base is therefore admirably adapted for incrustation-work, and the foil on which it is usually set serves as a reflector for the entering rays of light. The rose-pattern has several names, indicating the number of facets. If it has but twelve or less facets, it is called an Antwerp rose; if but eighteen or twenty, it is a semi-Holland; and a Holland rose, if it bears twenty-four facets. At the present time these gems are not in much demand, unless for incrustation-work, for which they are superior, both in effect and in adaptability to the surface of the object to be ornamented.

The form which appears to exhibit the splendors of the gem to the best advantage, is that known as the brilliant, and is rightly named from its effects. It was discovered in Italy, in the latter part of the seventeenth century, by Peruzzi, of Venice, which city was then one of the chief gem-marts of the world. The conclusions which led to the adoption of this shape were derived from experiments upon colored stones. This form of the brilliant is that of the ancient deep



table modified by receiving thirty-two facets above and twenty-four below its girdle. The great relative depth of the gem, aided by the numerous facets of the sides, appears to increase the natural refractive power of the stone by confining, as it were, the rays of light inside of it. Another pattern, called the brillolette, shows the beautiful qualities of the gem to great advantage. It is formed like two rose-diamonds joined together at the base; or may be flattened and elongated like an almond, and faceted all over with small facets. This is the form of the Sancy, and should have been given to the Koh-i-noor and the Star of the South. The Austrian yellow diamond is of this pattern, and was probably cut in India. And it is thought that the famous twelve Mazarin diamonds were also cut after this pattern. The star-pattern, which was invented by Cane, is but little used at the present time.