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FIRE IN THE EARTH
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mantina.
The government ordered the entire gold-mining population out of the
area and mining rights were placed in the hands of a few favored
planters, using slave labor.
Europe
didn't like the news about Brazilian diamonds, which threatened a flood
of the stones. Owners of Indian stones, fearful that the value of their
gems would suffer, spread stories that the Brazilian product was soft
and of inferior grade, but the Portuguese traders cleverly eluded this
by sending the stones first to Goa, reshipping them to Europe as Indian
diamonds and breaking the news gradually to European buyers. The fact
is, Brazilian diamonds, while reasonably good, are far inferior to the
Indian products, although harder, in some respects, than the South
African stones and for that reason valuable as boart, or industrial
diamonds.
But
as with India, the diamonds of Brazil have been found usually along
with gold in recent gravels in the basins of great rivers, such as the
Jequitinhonya in the state of Minas Geraes and the Paraguassu in the
state of Bahia. They also are found in the older plateau gravels. These
gravels have been derived from sedimentary rocks (also conglomerates
and sandstones and also of the Pre-Cambrian age). There is one
important difference between the alluvial deposits of Brazil and those
of India: In the Brazilian gravels, the diamond is found with various
associates of strange character; "and a wanted man," says L. J.
Spencer, the British mineralogist, in commenting on this fact, "can
often be traced through his friends." He goes on to say that these
associated minerals, some of which are gem minerals, are indeed taken
by the miners as indications of the presence of the precious stone.
They are usually found as small bean-shaped pebbles called "favas," and
include perovskite, anatase, rutile, chrysoberyl, tourmaline, kyanite,
etc., and
(14)
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