According to well known rules, there is one kind of cutting or faceting for the diamond or colorless gems and another for colored gems.
The brilliant cut, [figs. 5] and [6], consists of an arrangement of fifty-six facets, exclusive of the table and culet. This cut is sometimes improved by the addition of eight star facets around the culet, which brings the number of facets up to sixty-four.
The following are the proportions of a well cut diamond or colorless gem:
- ⅓ above the girdle, [fig. 6, A].
- ⅔ below "" " 6, B.
- The table 2⁄5 of the breadth of the stone, [fig. 6, C].
- The culet ⅙ of the size of the table, [fig. 6, D].
Fig. 5.Fig. 6.
These proportions do not refer to colored gems, which are cut thick or shallow to deepen or diminish the color of the stone. The step cut, [fig. 7], now principally used for emeralds, can be advantageously used for other colored stones.
The crowned rose cut, [fig. 8], is applied to small diamonds, and occasionally to colored gems. This cut consists of twenty-four facets, and a well proportioned rose is one half of its diameter in thickness.