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THE CUTTING OF PRECIOUS STONES 65
and
with flat or plane surfaces. Of the first, the curved surfaces, opaque
and translucent stones, such as the moon-stone, cat's-eye, etc., are
mostly cut en cabochon, that is, dome-shaped or semi-circular
at the top, flat on the underside, and when the garnet is so cut it is
called a carbuncle. In strongly coloured stones, while the upper
surface is semi-circular like the cabochon, the under surface is more
or less deeply concave, sometimes following the curve of the upper
surface, the thickness of the stone being in that case almost parallel
throughÂout. This is called the " hollow" cabochon. Other stones are
cut so that the upper surface is dome-shaped like the last two, but the
lower is more or less convex, though not'so deep as to make the stone
spherical. "This is called the "double " cabochon.
A further variety of cutting is known as the goutte de suif, or
the " tallow-drop," which takes the form of a somewhat flattened or
long-focus double-convex lens. The more complicated varieties of cut
are those appearing in the second group, or those with plane surfaces.
A very old form is the " rose " or " rosette " ; in this the extreme
upper centre, called the " crown," or " star," is usually composed of
six triangles, the apexes of which are elevated and joined together,
forming one point in the centre. From their bases descend a further
series of triangles, the bases and apexes of which are formed by the
bases and lower angles of the upper series. This lower belt is called
the " teeth," under which the surface or base of the stone is usually
flat, but sometimes partakes of a similar shape to the upper surface,
though somewhat modified in form.
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