Willmar tribune. [volume] (Willmar, Minn.) 1895-1931, 1910-07-20
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- RAIL has practically a monop-
oily of the worlds supply of
the black diamond, while the
United States is it's largest
market. It is found in La
Chapada and Lavras districts
OF the province of Bahia, Brazil,
where it is mined from river beds and
other alluvium. The miners sell their
find to agents Of exporting firms in
the city Of Bahia. It is calculated that
this port ships annually about $4,000
600 to $4,600,000 worth of black dia-
monds, and, with the adoption of
modern methods and machinery in
place Of the extremely primitive ones
formerly employed, the industry will
be tremendously stimulated. About
twenty-five years ago stone Of LOO
carats was found, followed by one OF
LOO carats, and in 1896 gigantic
stone OF 3,07S' carats, or 615 grams,
which was purchased by New York
house for $4,000 and broken up into
pieces of suitable size for diamond
drills. At present prices this stone
would be worth about $262, 900. Dur
ing the past ten years stones Of 400
to 800 carats have been discovered,
while they are frequently found weigh
ing from 100 to 200 carats.
Previous to 1870 carbonate was
practically valueless. From 1870 to
1872 it was employed as an abrasive
for cutting and polishing the white
gems, and thousands of carats were
sold at SO cents per carat, to be crush
ed to powder for this purpose. A few
years later, when carbonate was en-
ployed in diamond drilling, it sold at
from 81 to 81 carat. Between 1895
and the present the market value has
fuctuated between $25 and $85 carat.
this high price being caused by the
decline in the supply of carbonate in
the past ten years, while the demand
has increased. In connection with the
subject Of black diamond consumption
in drilling, it is interesting to remark
that In digging the drill hole at Ryb-
mix (Paruschowitz), Upper Silesia,
which attained depth of nearly 1000
feet, upward of $4,000 worth of car
bonado was used.
The conditions are entirely differ
ent from those of Africa. The gravel,
sand, and other material containing
diamonds lie In or near the beds of
streams and rivers. and have been
washed down by erosion from high
"chapadas" or plateaus, which are
probably the original matrix in which
Brazilian diamonds were formed. AS
is natural, gold and variety of other
substances, such as itacolumnite,
divine. limestone, hematite, granite,
gneiss, and clay are associated with
the diamonds. The Acknowledging
material of Brazil consists of a con-
glomerate, sometimes interbedded with
hard yellow sandstone, which is wash
ed down through erosion by rivers, or,
in some cases, may be badly decom-
posed and rotten rock. Fossils are
generally lacking. The deposits often
consist Of schists and schistose clay,
demonstrating clays, reddish earth,
granite and gneissic formations, and
pebbles Of various sorts.
The states of the republic which
have yielded diamonds are Minas
Geraes, Parana, Bahia, Goyaz, and
Matte Crosse. It is in the first named
that Diamantina, celebrated for the
rich diamond mines in its vicinity, is
situated. The city is well built and
lies at the headwaters of the Jequitin
honha, or Diamond, river, a stream
$50 miles long, which empties into the
Atlantic at Belmonte To the east OF
Diamantina is the peak of Mount
1tambe, $3.50 feet, in the Sierra Espin
AGO Range. The mines are situated
north Of Rio de Janeiro, 800 kilo
meters, or 497 miles, north of Ourc
Preto, the capital of Minas Geraes
The territory in which they are stu
ated forms vast ellipse, 80 kf1o
meters, or SO miles, by 40 kilometers
or Is miles, in plateau 1000 to 1,2O(
meters $3.50 to 1887 feet), contain
ing number of valleys cut by thu
Jequintinhonha and its left tributaries
Ribeirao do Inferno, Rio Caethe, etc.
and also by the Sac Francisco's at
| fluents which flow to the northwest. il
very different basin.
| Although diamond mining has beer