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THE DIAMOND.
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IQ!
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diamond, considered the most faultless brilliant known, and
the Koh-i-noor, in which proportion is sacrificed to save loss of weight,* the breadth being too great for the depth, consequently it is deficient in brilliancy. The forms of cutting precious stones vary ; they are generally classed as table, rose, brilliant, brilliolette, step, and
cabochon. What is called step-cut is adapted for many of the transparent, colored stones, while the translucent and the opaque varieties are usually cut en cabochon — that is, without facets, or as convex, concave, double convex or having one flattened and one convex surface. The garnet, it is claimed, is the only transparent gem cut to advantage en cabochon ; others, like the ruby, sapphire, and zircon, lose in brilliancy by this method. All diamonds, several centuries ago, were cut with a square
or oblong plane on both sides, one being much smaller than the other ; they were designated table or Indian cut. At a later period a form called the rose came into fashion, which consisted of a flat base and a dome above, usually with a double row of facets presenting a figure like a half polyhedron. The rose is much less expensive than the brilliant cut, and can be fashioned out of very flat or cleavage stones. It has been stated that rose-cut diamonds are sometimes of a size so small as to require fifteen hundred to weigh one carat, which seems incredible when the extreme delicacy and skill required for such work are considered. This style of cutting receives different names, according to the number of facets the stones display. The brilliant is a later invention, and the one most in use ;
its origin has been referred to Peruzzi, of Venice, of the seven- * As a rule, the diamond loses from one-third to two-thirds of its weight by cutting and polishing.
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