164 THE DIAMOND MINES OF SOUTH AFRICA
in Brazil for the year, estimated at 40,000 carats, is at present
insignificant. . . . The most important diamond districts in Brazil
are Diamantina, Grao Mogul, Chapada Diaman-tina, Bagagem, Goyaz, and
the same report the quantity of diamonds produced in India for 1898 is
given at 170 carats, valued at 10,873 rupees, and for 1899, 124 carats,
valued at 8011 rupees.
New South Wales. The
existence of diamonds in New South Wales was made known as early as
1859, by Rev. B. W. Clarke, who received in that year several specimens
from the Macqua-rie River, Burrendong, and Pyramul and Calabash Creeks.
It was not, however, until the rush for the gold diggings, seven or
eight years later, that any considerable number of diamonds was found,
when the gold digging along the Cudgegong River, about nineteen miles
northwest of Mudgee, brought to light diamonds in an old river drift,
generally covered with a layer of basalt.
diamonds were sparsely distributed through the gravel, and were usually
small, the largest of the stones, a colorless octahedron, weighing only
5-5/8 carats. Later, other diamond fields were opened near Bingera, on
the river Hoclon, and in the tin-mining districts near Inverell. The
diamonds occur in alluvial gravel wash in the beds of ancient rivers.
This gravel carries tin ore or gold in places, and usually one or both
of these are won with the diamonds. These ancient river channels
resemble those in California, in which diamonds were occasionally found
with the gold. Many of these rivers lie buried beneath lava hundreds of
feet thick, and the diamonds are won by driving long tunnels and
drifting out the gravel lying on the bed rock.
C. Le Neve Foster gives the production in New South Wales for 1898 as
16,493 carats, valued at £6060, and for 1899, 25,874 carats, valued at
£10,350. These figures give an average value per carat of seven
shillings and four pence and eight shillings respectively, as compared
with forty shillings per carat for De Beers and Kimberley mines.
Borneo. The estimated production of diamonds in Western Borneo was 1190 carats for 1897, and 1950 carats for 1898.