Cutting Diamonds and Other Gems 197
Occasionally
a gem does appear which, without artifice, may plainly show its
qualifications for high rank in the court of gems; but, in the main,
the development of its beauty to a high degree necessitates cutting and
polishing. The highly specialised work of the diamond cutter or
lapidary involves compliance with geometrical principles and rules;
adaptation to the place occupied by the gem stone under treatment; a
knowledge of the clearly defined science of crystallography, especially
with regard to the planes of cleavage; careful consideration of the
stone's degree of hardness, brit-tleness, and a thorough acquaintance
with the established forms of cutting and the results achieved through
them with different kinds of gem minerals and their chromatic varieties.
The
art of gem-cutting has progressed gradually from the crudest
beginning. Man's first attempts to artificially improve the appearance
of gem stones extended only to polishing the natural surfaces; later,
the worker essayed to round the rough corners, and in the course of the
evolution of this art, efforts were made to reduce the stone to a
symmetrical shape. Gem-cutting by Oriental workmen, in the island of
