setting, when it will appear nearly white, the blue material correcting the yellow hue of the gem.
For
the localities where diamonds have been or are found reference may be
made to the works named in the brief bibliography in the present
manual. The story of the diamond-fields of the world is full of
romantic interest. India, Brazil, Borneo, and South Africa have all
furnished most curious contributions to the long list of adventures,
discoveries, and disasters connected with the diamond.
Until
January 25th. 1905, when the Cullinan diamond weighing 3,032 carats, or
621-1/2 grams, was found in the Premier mine 20 miles W.X.W. of
Pretoria, the largest known diamond was that from the Jagersfontein
mine, Orange River Colony, discovered on June 30th, 1893. It weighed
971-1/2 carats, but owing to an imperfection the largest brilliant cut
from it weighed only 239 carats. It has been called the " Jubilee " and
the " Excelsior," and is of high quality. The largest diamond found at
Kimberley was an octahedron of 503 carats, but this stone was full of
black spots. Amongst the diamonds obtained from the river Vaal diggings
the largest is a rounded pebble weighing 330-1/4 carats, but it is not
of good quality.
It
has been estimated that the value of the diamonds added to the world's
stock irom the South African mines is more than £85,000,000. Even in
one year (1903) the value of diamonds exported from Cape Colony was
close upon £5,500,000. By the side of these figures the yields in
ancient days of India, and, since the vear 1725, of Brazil, do not seem
large. At the present time diamonds are still found in Brazil, while
new sources have been discovered in New South Wales, Borneo, and
British Guiana. From the last named colony 173,744 stones were exported
in 1902, but they were very small, for they weighed altogether no more
than 11,518 carats.
The winning of diamonds and their mode of occurrence in the
