WHILE precious stones are cut to many different forms, there
are, nevertheless, but a few general types of cutting. These may
be classified as follows: First, the "cabochon" (Fig. II) type
of cutting; second, the old "rose" (Fig. 12) type of cutting;
third, the brilliant (Fig. 13); fourth, the step cutting (Fig.
14). Cabochons. Of these the first, or cabochon cutting, is
probably the most ancient. The term comes from a French word
signifying a bald pate (caboch, from Latin cabo, a head). The
usual round cabochon cut closely resembles the top of a head in
shape. Cabochon cut stones usually have a flat base, but
sometimes a slightly convex base is used, especially in opals
and in moonstones, and some stones of very dense color are cut
with a concave base to thin them and thus to reduce their color.
The contour of the base may be round, or oval, or square, or
cushion shape, or heart shape or of any regular form. The top is
always smooth and rounding and unfacetted. The relation of the
height or thickness to the