|
CHAPTER FOUR
|
||
|
|
||
|
BRAZILIAN DIAMONDS
|
||
|
|
||
|
Diamonds were discovered in
Brazil in 1725. The Brazilian diamonds like those of India occurred in
gravels and conglomerates, and much of the later mining operations to
recover them have taken the form of dredging the river beds and washing down the gravel deposits by water under pressure (hydraulic mining).
In
Brazil the earth, which is gravelly, is washed in troughs, much after
the method of the early California gold hunters; and the diamonds, if
any, are found among other pebbles at the bottom of the trough. Such a
system is very severe upon the sight of the workers; children are
always the best washers, and a worker's eyes cannot usually be trusted
for this fine work after he has reached the age of twenty-five years.
If magnifying glasses were used to find the diamonds in the sand much
time would be saved and there would be less loss.
It
is during the process of sifting that most robberies are effected. Few
workers swallow the diamond, not because it is considered poisonous, as
by the Hindu, but because of the difficulty of doing so unobserved. The
civilized thief
28
|
||
|
|
||