188 PRECIOUS STONES.
The diamonds of the Borneo mines occur in beds from ten
to thirty feet in depth, at the foot of mountains, the largest and
best specimens being found in the lowest strata. The Chinese
worked many of these mines until the middle of the present
century, when they were driven away by the natives, a measure
which was immediately followed by a decline in the supply.
Diamond-cutting. — Having secured these valuable treasures
at great expense and trouble, the question is pertinent, what
shall be done with them ? If the fortunate possessor is only
a connoisseur, he will arrange them in a cabinet for the admiration of himself and friends, but if he is fond of personal ornaments, he will want them cut and polished, then mounted in a
convenient form for use, since in their native state they are not
adapted for jewelry, and need the skill of the artist to develop
their inherent beauties.
The practice of cutting and polishing gems is not as modern
as some writers are inclined to believe, but was known very
early in the history of art, if Hill and others are correct in
their statements. It is thought the Phoenicians learned the
process of cutting precious stones from the Assyrians, and
soon diffused it through all their colonies, and that cutting and
mounting them were understood in Great Britain during the
Roman period. It is not positively known that the diamond
was included in their list of gems ; neither is it certain it was
not.
We meet with conflicting statements in regard to the origin
of the modern style of cutting and polishing diamonds. It has
frequently been ascribed to Louis de Berghem or Berquem, of
Bruges, of the fifteenth century, and that the first diamond he
cut was for Charles the Bold, Duke of Burgundy. On the
other hand, it is maintained that the art of cutting this gem
was known long before his day, as is proved by the existence
