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Ch. 10: Diamond

Ch. 10: Diamond Page of 401 Ch. 10: Diamond Text size:minus plus Restore normal size   Mail page  Print this page
THE DIAMOND.
ICS
covering a defective specimen with facets, in order to conceal
its imperfections.
The ancients may have used the diamond-point for cutting
and filling in the details. It is certain they used the corundum for the softer gems, a practice introduced into Greece from
the East. In modern finish, the work is accomplished by a
revolving disc and diamond powder, or carbonado ; whence the
metaphorical expression, "diamond cut diamond." The earlier
Gnostic gems were worked by the diamond-point, while the
later specimens were submitted to the wheel, so that an expert
can easily distinguish an ancient intaglio from a modern
imitation by the method used for cutting it. The stone to be
operated upon is first split, and, as it consists of a series of
layers, this can be accomplished in the direction of these
laminae ; the next step is to cut them, which is accomplished
by rubbing together two diamonds of nearly equal size,
cemented into a handle ; the powder made by erosion is
preserved for polishing. This work is performed upon a disc
of soft iron, made to revolve very rapidly upon a horizontal
plane covered with powder mixed with the purest olive oil.
When one facet is completed, the stone is changed in its position, so as to present another side until it is completed ; more
than one stone can be worked at the same time. The process
of cutting requires the greatest care and nicety, since the least
carelessness may spoil the gem. According to Emanuel, the
finest specimens are sent to the London market, those of a
second rank to Paris, and the inferior stones are exported to
the United States, Turkey, and other countries. If this is
correct, London is the best place for the purchase of these
gems, where quality is the first consideration ; but it has been
stated, on the other hand, that the most costly finished diamonds find sale not only in England, but also in France and
Ch. 10: Diamond Page of 401 Ch. 10: Diamond
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