Ceredo advance. [volume] (Ceredo, W. Va.) 1885-1939, 1910-08-03

ity 70 be worked. The first of these.
which is found suitable for the dia-
mond.bearing streams OF the Diaman-
Una district, somewhat resembles
placer gold washing. The process con-
sists primarily in digging out sand
and gravel, which are put into small
wooden bowls, each capable OF holding
or 10 pounds. The native miners
then proceed in Indian file with their
loads TO some convenient part of a
river or stream, where they laborious.
ly wash out their material, gradually
getting rid of all lighter particles and
debris until the hidden diamonds.
whose specific gravity is 3Ib. reveal
themselves through their weight and
peculiar luster. Iron pans with small
perforated holes are sometimes used
10 hasten the process of extraction. A
modification of this plan. where
considerable pit has been excavated.
consists in finding a curve in the riv-
er some distance above. with a natural
fall OF 20 or 80 feet, and diverting
thither part OF the stream through
an artificial channel
A different method OF mining has TO
be employed in the localities called
"chapadas," or plateaus. where dia.
monds are imbodded in compact. some
what resistant, conglomerates.
small reservoir, or If necessary. two
or three reservoirs, are built. rude
dams are placed at various points
across the nearest available river. and
win the increased water power thus
obtained the conglomerates are washed
down ravine TO the desired lower
level, where the process of further
diamond extraction may be continued
Primitive as are the processes de.
scribed, they have yielded in the mast
one hundred and eighty years sur
prlsingly rich returns. According IN
the pest authorities, the total Bra
zllian diamond production, including
the extensive contraband trade prac.
Used during the Portuguese colonial
regime. Is estimated at 10000 OO0
carats, or 2H metric tons. The total
export value OF diamonds OF every sort
from Brazil In 1906 is conservativeIy
calculated at about s5,000,0OO
One OF the first enterprises to install
dredging and hydraulic machinery for
the extraction OF diamonds such as
the alluvial diamantiferous deposIts of
the Republic require was the Boa Wis.
ia company. in 1899 formed in Paris
with a capital of 1000 900 francs. or
@4oO,OOO. Their mining concessions
were situated at Boa Vista, on the
north bank OF the Sac Francisco river
above the Falls of Paulo Alfonso. and
about 300 miles from the Atlantic.
me Brazilian diamond bearing de.
posts so far discovered are all alIu.
vial and surface. and they possess
many natural advantages over the dia,
V1antiferous fields of South Africa
winch, as has already been explained
are DRY diggings. requiring the most
expensive processes and machinery
and every deEice that humizT ingenu
lty can invent for the successful ex
traction OF diamonds In Brazil. on
the other hand, the diamonds con.
cealed can be easily extracted by
means Of hydraulic and dredging an
paratus. A network of rivers anG
streams affords an unfaillng and co.
pious water supply and power. There
Is no deep mining 10 be done. az iu
the case in South Africa. Only very
small portion Of the probable total
Brazilian alluvlum has been explored
and the river gravels, except I'm the
reaches OF only moderate deptb are
untouched. Moreover, these graveIS IN
many cases carry enough gold 10 nav
Tor dredging, and even platinum NAV
be found.