The watchman and southron. [volume] (Sumter, S.C.) 1881-1930, 1922-09-30
How Diamonds Are Mined


in this case TO peg out claims in a
newly discovered diamond field
was mentioned in recent dispatches
from South Africa. This new dia-
mond country opens up possibili-
ties of a rival to the great Kim
berly diamond field in the same
general region. the worlds great
est source of the sparkling white
gems.
The methods of mining diamonds
at Kimberly, which may be fol-
lowed in the new fields if the for
nation proves the same. are out
lined in bulletin from the Wash
ington. y. c.. headquarters of the
National Geographic Society.
Like Needle i'm Haystack
The mines at Kimberley" says
the bulletin, ..are in very ancient
volcanoes which ages ago lost all
sembiance of activity. But during
their youth the great heat andspres-
sure Of these volcanoes created gi-
gantic laboratories in their depths
in which Thousands Of the hard
white carbon crystals, which, are
diamonds, We're created The pre-
cious little Jumps are embedded in
a great volume of worthless rock
known as blue ground and un-
der old conditions were as hard to
find rs the proverbial needle in a
thaystack. But just as a clever
searcl1er could probably locate his
needle with a powerful magnet. de-
spite the straw, so engineers have
evolved mechanical means clever
ly to separate the few tiny dia-
monds from the many tons of dirt
in which they are, hidden.
1.-The effectiveness with which
Nature has concealed the crystals is
evidenced by the fact that the blue
ground brought up from the depths
of the mines and carrying its price
less gems, is spread out in the open
for four months to q year to the
weather. The diamonds are per-
fectly safe; for officials who have
walked over the weathering floors
for many years assert that they
have never found diamond in this
way. As the blue ground weathers
/ it crumbles. and great harrows
like those used on the bonanza
farms of the West, are dragged
over it to. facilitate the process.
Gems Trapped in Grease
Eventually the material is
broken down into relatively fine
particles. It is then taken in truck
loads to the mechanical plant Of
the mine for treatment. The
ground is mixed with water in great
mixing machines ard passed over
screens of fine wire meshing.
when as much as; possible of
the foreign material has been re-
moved in this way the. coarse resi-
due, containing the diamonds, is
passed over sloping, vibrating ta-
bles covered with thick grease. Be-
cause of some little understood
physical property, diamonds stick
TO the grease while the worthless
material flows over the edge OF the
tables. The grease with its load
of CRYSTALS is then scraped into a
perforated container and heated by
steam. The grease melts away and
leaves the small but highly valu-
able object of these months of work.
s.How widely spaced the dia-
uords. are in their matrix OF earth
can be shown best perhaps by
comparison of volumes. The earth
taken out in year by the largest
mining company in the field. would
form cube more than 4SO feet
in each dimension. This would fill
a. large city block to a height OF
more than thirty stories. The dia-
naonds found in this vast amount
Of earth would fill only two or
three desk drawers or a cubical box
less than three feet in each dimen-
son. But these few pecks of stones
for which nounatin was moved
were worth perhaps in excess Of
s25 100000.
Iaborers Voluntary Exiles
zone Of the most striking fea-
lures of the mining of diamonds
by the large companies in Kimberly
is the existence Of the unique labor,
compounds. Since diamonds are
so easily stolen. only those native
laborers are employed who Will
agree OF enlist for at least three:
months and remain for that pc.
riod, (when not in the mines, or
on the 'f1oorso within walled. en-
closure. In the largest compound.
covering more than four acres, D.
600 men live. Not only are these
compounds surrounded by high
walls. but they are also covered
with fine wire netting SO that dia-
monds cannot be thrown outside to
confederates.
"Laborers entering or leaving 4 +.
compound must go through pro-
cedure not unlike that when enter
ing a foreign country having strict
immigration and customs laws.
They must pass a health eSamina-
ton and if diseased are rejected Or
placed in quarantine. Only certain
articles may be taken into a COM
pound, and no boots, shoes or other
hard or solid materials may be taxi
en- out--only clothing which has
been searched. In the largest OF
the compounds, where some labor
ers have chosen to stay for years.