Although a finely developed diamond, ruby, or other crystal is
sometimes found and used for jewelry, the beauty of a precious stone
generally remains hidden within a rough and unsightly exterior until
the lapidary’s art reveals the gem.
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.
[Illustration: 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.
[Illustration: FIG. 7. FIG. 8.]
[Illustration: FIG. 9. FIG. 10.]
To the smaller and more common roses only twelve facets are given.
Besides the above-mentioned forms, there are the:
Huitpan, or single cut.
16 facet " double "
24 " " single brilliant.
Cabochon " carbuncle.
Star cut, fig. 9.
Degree or rose cut, fig. 10.
The last two beautiful forms of cutting are frequently given to fine
paste or imitation diamonds.
Of late years nearly all gems have been cut quite round, and in many
instances with a sacrifice of size and brilliancy.