dustry was in a thriving state during the years from
1640 to 1680, during which time he made six journeys to India to
purchase gems. He speaks of Borneo as another source of diamonds, but
most of the diamonds of that time were furnished by India.

"GOLCONDAS." Indian diamonds were noteworthy for their magnificent
steely blue-white quality and their great hardness, and occasionally one
comes on the market to-day with an authentic pedigree, tracing its
origin back to the old Indian mines, and such stones usually command
very high prices. One of a little over seven and one half carats in
weight, in the form of a perfect drop brilliant, has lately been offered
for sale at a price not far from $1,000 per carat. Such diamonds are
sometimes called "Golcondas" because one of the mining districts from
which the fine large Indian stones came was near the place of that name.
Some of the stones from the Jaegersfontein mine in South Africa resemble
the Golcondas in quality. Many of the large historical crown diamonds
of Europe came from the Indian mines.

The stones were found in a sedimentary material, a sort of conglomerate,
in which they, together with many other crystalline materials, had
become imprisoned. Their original source has never been determined. They
are therefore of the so-called "River" type of stone, having probably
been transported from their original matrix, after the disintegration of
the latter, to new places of deposit, by the carrying power of river
waters.

The Indian mines now yield very few stones. The United States Consular
reports occasionally mention the finding of a few scattered crystals but
the rich deposits were apparently worked out during the seventeenth
century and the early part of the eighteenth century.

In 1725 and in the few following years the Brazilian diamond fields
began to supersede those of India. Like the latter, the Brazilian fields
were alluvial, that is, the materials were deposited by river action
after having been carried to some distance from their original sources.

BRAZILIAN DIAMONDS. The diamonds of Brazil also resembled those of India
in quality, being on the average better than those of the present South
African mines. It may be added that even the African diamonds that are
found in "river diggings" average better in quality than those of the
volcanic pipes which form the principal source of the world's supply
to-day. There seems to be a superabundance of iron oxide in t