Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-06-01
Extracting the Precious Stones.

4
] would hold the gems.
Extracting the Precious Stones.
After the end OF each days work the
pans through which the mud has passed are
cleaned up and the contents, consisting of
| diamonds and other heavy but valueless
minerals are sent to a pulsator. where
| they are sized by passing through steel
| sieve with holes from one-sixteenth to fve-
eighths of an inch in diameter. The finest
sise are conveyed to a washing pan and
the coarser ones pass 10 revolving picking
| tables, where diamonds of the largest si3e
| may be seen and removed without being ex-
posed TO the risk of being crushed by
/ further pulverization. The remainder pass
through screens into pointed boxes from
which they are carried over series OF
| trays covered with thick grease. This Is a
| curious process. Formerly all of the par
ticles that did not go through the screens
were dropped upon corting tables, where the
diamonds were picked out by hand. This
was slow, tedious and imperfect process.
A great many gems were lost and carried
away with the tailings, until Mr.. Fred
Kristen. one Of our employees, asked to be
allowed to catch the diamonds by placing
coat of grease upon the surface Of the
table upon which they were dumped Kir-
stem had noticed that oily substances such
as axle grease and white and red lead
adhered very tenaciously to diamonds and
argued to himself why should not diamonds
adhere to grease?
I'm this way he made the remarkable
discovery that jewels alone will adhere to
grease while all other minerals will pass
over It, Since the discovery of this curious
affinity 1t has been demonstrated that ru-
bies emeraids and sapphires can be caught
streams from the washers now pass over
slopfng tables made of corrugated iron and
thickly covered with grease. Only about
one-third of per cent of diamonds escape
the first table, while the remainder are re-
covered almost to a stone on the second
table. This grease will not cling to any
thing but precious stone. Small bits
of iron pyrites brass nails and miners
boots. pieces of copper from the detonatons
used in blasting and an infinite variety of
other metallic articles will pass over 1t
without being detained an instant, but it
VIII catch diamond every time.
Sorting and Selling the Jewels.
1.-THE diamonds are placed on sorting Ia
bles, where they are carefully separated
with reference to size, color and purity,
are then washed In a mixture of acids to
clean them of extraneous matter, and are
made up in parcels to be delivered to the
representative OF the syndicate Of London
diamond merchants who have purchased
the entire annual product of the De Beers
mines for several years
All the sorting Is done by the trained
naked eyes of experts. No magnifying
glass Is ever used. We employed ten sort
ers, two women and eight men, all Euro
peans, and trained apprentices to succeed
them In case any should leave. More than
twenty million dollars worth of diamonds
pass annually through their hands. For
the safe-keeping of the gems, there Is a
strong vault Of very thick concrete fire
and burglar proof, secured by several locks
Of the latest designs. with different keys
which are kept by the several officers of
the company. 1t was necessary for all of
them to be present at the opening and
closing of the room. In addition to these
ynrna {n,c fI1r. ~ %-tz \
armed guards.
How Diamonds Are Valued.
after the diamonds are sorted they are
put into little square tin boxes which fit
into tin cases like dispatch boxes, each of
which will hold about forty of the smaller |
ones. They delivered to the buyers |
at the Office of the latter and paid for on |
delivery in cash or In bills on London Dia- |
monds have fixed value, which is reach
ed by a recognized formula, according 40 |
the number of carats. The word carat |
is derived from the Greek Iteration" the |
fruit of variety of acaia acacia whose |
seeds weigh four grains avoirdupois and |
are so remarkably uniform that they serv- |
ed In ancient times as the most convenient |
measures of the value of precious stones |
To compute the worth of a diamond the |
weight of the cut stone should be doubled |
to offset the loss of one-half In working
Ihen this Inquire should be squared and the |
product multiplied by the price per carat |
Thus cut stone Weighing one carat would |
be valued by multiplying two by two by
Two, or at eight pounds sterling, and stones |
weighing five carats by multiplying ten by |
ten by two, or two hundred pounds sterling. |
by this method of calculation mineralogi- |
cal freak known as the Culinan diamond
the largest ever known, which was picked |
up In the Bultfontein mine two years ago |
was valued at s45 100000 |
The stock Of the De Beers Mining Com
pany consists OF 100000 shares of a par |
value or $3.50 share. They are now sell
ing at 800 share on the open market and
nave sold as high as $115 a share. The
nlnes were formerly owned by Alfred Belt |
Barney Barnato Cecil J. Rhodes ana seu
erai other gentlemen, but the company is |
now controlled by the Rothschiids and |
other European capitalists