PRECIOUS STONES. 55
to
larger stones of good quality, smaller stones being cut in some of the
many modifications of the brilliant pattern, such as the double
brilliant, or even more simple forms. An English-cut stone can often be
distinguished by the greater accuracy given to the angles of the
facets, so that the resulting gem is exactly symmetrical.
Among
the many other forms into which gems are cut, a few may be mentioned :
for transparent stones, besides the brilliant-cut there is the "
step-cut " ; in this the facets are elongated, the longer edges being
parallel so as to form a series of steps. The crown may have two or
three steps and the culasse five or six or more; table and collet are
formed as in the brilliant. A step-cut stone may be square or six
sided, etc., just as a brilliant; this form is shown in the square type
in Fig. 5. Two older forms of cut have already been referred to: the
"point," in which the octahedral crystal faces, or the octahedral
cleavage planes were simply rendered symmetrical in outline and
polished, and the " table-cut," in which a table and collet were formed
(Fig. 4). Another type is the " rose." In this the gem is worked into a
series of, usually, triangular facets, arranged in two series, an upper
series forming the crown or star, and a lower series, that called the
teeth; the under surface is a simple plane (Fig. 6). More rarely stones
are cut into a general pear shape, worked all over with small
triangular facets, " briolette; " or into a "rosette," which has the
form of two rose-cut stones joined together by their large plane
surfaces ; occasionally a very thin stone is cut as a "
half-brilliant," which is similar to the crown only of an ordinary
brilliant, the lower part of the stone consisting of a large plane, as
in the rose.
