THE CUTTING OF PRECIOUS STONES 63
skill
so great as to be found only in the expert, for in stones of great
value even a slight mistake in the shaping and cutting would probably
not only be wasteful of the precious material, but would utterly spoil
its beauty, causing incalculable loss, and destroying altogether the
refrangibility, lustre and colour of the stone, thus rendering it
liable to easy- fracture : in every sense converting what would have
been a rare and magnificent jewel to a comparatively valueless specimen.
One
of the chief services rendered by precious stones is that they may be
employed as objects of adornment, therefore, the stone must be cut of
such a shape as will allow of its being set without falling out of its
fastening —not too shallow or thin, to make it unserviceable and liable
to fracture, and in the case of a transparent 'stone, not too deep for
the light to penetrate, or much colour and beauty will be lost. Again,
very few stones are flawless, and the position in which the flaw or
flaws appear will, to a great extent, regulate the shape of the stones,
for there are some positions in which a slight flaw would be of small
detriment, because they would take little or no reflection, whilst in
others, where the reflections go back and forth from facet to facet
throughout the stone, a flaw-would be magnified times without number,
and the value of the stone greatly reduced. It is therefore essential
that a flaw should be removed whenever possible, but, when this is not
practicable, the expert will cut the stone into such a shape as will
bring the defect into the least important part of the finished gem. or
probably sacrifice the size and weight of the original stone by cutting
it in two or more pieces of such a shape that the cutting and
