I visited a mine that was completely different from
all the others that I had seen in Africa. Instead of
an open pit, the mine was entirely below the surface.
In the entire world, there were then only six such underground
mines. All of them were in South Africa: five hemmed
in the mining city of Kimberley, and the sixth located
400 miles northeast in the Transvaal. The Wesselton,
located only about a mile from downtown Kimberley, was
the deepest of these diamond mines. The mine shaft extended
3,300 feet below the surface, which is deep enough to
accommodate both towers of the World Trade Center in
New York, stacked one on top of the other.
Before I was allowed to descend
into the Wesselton, I was taken to a spotlessly clean
changing room and provided with the necessary mining
gear. This included steel boots, a white jumpsuit, a
steel helmet with a built-in lantern, and a portable
battery, which I strapped around my waist. I then proceeded
to the mine shaft where I was met by Edward Robinson,
a soft-spoken South African, who had been born and raised
in the mining area around Kimberley.
At the top of the mine shaft, we
stepped into a steel cage, the size of a large freight
elevator. The door clanged shut. Robinson pressed a
button, and with a sudden jerk, we began hurtling down
the mine shaft. We were falling at a rate of twenty
feet per second, or twelve miles an hour. Even at that
speed, it took slightly more than two minutes to reach
the mining level, 2,500 feet below the surface.
From all the films I had seen about
coal mining, I expected to step out into a dark tunnel
where men were hacking away at the rock with picks and
shovels. Instead, I found myself standing in an enormous
well-lighted and air-conditioned chamber. The ceiling
was at least fifteen feet high, and there was a road
in it wide enough for a two-ton truck.
"We call this the block cavina method,"
Robinson said. "It works on the same principle as punching
a hole in the bottom of a bottle to drain the liquid
out." He explained that rather than scooping out the
kimberlite ore from above, as is done in open-pit mining,
a shaft is drilled in the bedrock that encases the volcanic
pipe. Once underneath the main body of ore in the pipe,
or "the bottom of the bottle," as Robinson put it, a
series of tunnels that run parallel to the surface are
dug under the pipe. This is the "mining level." The
kimberlite above, loosened by dynamite, then simply
pours into the tunnels.
Robinson's attention focused on
something happening at the end of the tunnel we were
entering. He held up his hand. Suddenly, everyone around
A voice counted in Afrikaner "...
schwi ... di ... ein." Then there was a loud explosion,
followed in rapid succession by four other blasts. I
could feel the reverberations of the concussion and
smell burnt sulphur in the air.
"They're dynamiting ahead," Robinson
calmly said. The dynamite came, he explained, from De
Beers' own explosive factory, which was the largest
Robinson motioned to follow him into
the tunnel. At one end, kimberlite ore was flooding
in. A black worker operated a powerful winch. It manipulated
a bulldozer blade about thirty yards away. The blade
scraped kimberlite ore through a hole in the floor of
The ore poured into a train of hopper
cars on the level below. It was fully automated. The
train arrives under the opening just before the scraper
forces the ore through it. When full, it then shuttles
over to the mine shaft where it dumps its ore. A belt
of continuous buckets then bring the ore to the surface
and deposit it on the conveyor belt. In all, this highly
mechanized form of mining required about 165 men, including
supervisors, below ground. Most of the workers were
black, and the supervisors were white.
Robinson said that it was the white
labor unions that insisted that the whites be given
supervisory positions, rather than the blacks. He explained
that some 40 percent of the black workers were tribesmen
from Lesotho on seasonal contracts (while in South Africa,
they lived in De Beers-- owned dormitories, called "hostels,"
and received about $40 a week in salary).
Before Robinson became manager of
the Wesselton mine he had worked at one of the Anglo-owned
gold mines. The mining level there was more than one
mile below the surface of the earth, and the temperature
of the walls in the cramped tunnels reached 12o degrees
Fahrenheit. Unlike kimberlite, which when loosened flows
by gravity into the mining tunnels, gold ore must be
chiseled out of bedrock with picks and drills. "The
seam at times was no wider than a pencil line, and there
were literally thousands of men chipping away at it,"
he said. "There are more workers in a single gold mine
than in all the De Beers diamond mines in South Africa."
When we returned to the surface,
I was momentarily blinded by the glare of the sun. It
was also at least thirty degrees warmer above ground
than below. We then took another elevator to the top
of the tower of the mine shaft, which was about ten
stories high. From this vantage point, the entire history
of the mine could be clearly seen.
Robinson pointed to a yawning pit,
almost 500 feet deep, across the parched earth. It was
the original mine. Like all pipe mines, the Wesselton
had begun as an open-pit mine. At some point it became
too deep to haul out the kimberlite ore profitably.
"The only way it could be mined," Robinson said, was
"to get the ore out from below."
The half-mile-deep mine I had just
visited was below that pit. The continuous belt of buckets
dumped the ore from the shaft onto the conveyor belt.
At Wesselton, according to Robinson, more than 6,ooo
tons of kimberlite ore is brought up the mine shaft
every day by this automated equipment. Yet there are
only some 1,400 carats of diamonds recovered from this
mass of ore. Of these, only about 150 carats are of
gem quality. "More diamonds are recovered per ton from
the waste dumps than from the mines", he said, pointing
to the mountains of kimberlite ore that had been spewed
out of the separation plants over the years.
Some of this waste was more than
a hundred years old. Diamonds smaller than a tenth of
a carat were difficult to sell then , and De Beers had
not invested until recently in sophisticated technology
for recovering a high proportion of the minute diamonds.
Now, however, with factories in India polishing diamonds
as small as 1/25th of a carat, there was a ready market
for these "small goods."
Even with the "mining" of the old
dumps, Robinson admitted that the Wesselton and the
other mines around Kimberley were rapidly reaching the
point of diminishing returns. He estimated that the
De Beers mines in Kimberley could begin to run out of
gem diamonds as early as the 1980s. Kimberley might
then become a ghost town.
It was here that the diamond invention
was devised, and the inseparable connection between
Kimberley and De Beers, which is,, still evident when
one walks through the town. The zig-zagging streets
follow the pattern of the original mining claims. They
then end abruptly in an enormous crater that the city
literally hangs over. It is about one-quarter of a mile
deep and partly filled with rain water, which reflects
the buildings on the edge of the city. This abyss is
called the Big Hole, and it is what remains of the Kimberley
Central mine. This was the deepest open-pit mine ever
dug. The ore was lifted out by a system of ropes and
pulleys that looked like a giant spider web. Before
it was finally abandoned in 1914, it produced over three
and a half tons of diamonds. This flood of diamonds
not only transformed Kimberley into a city, but it necessitated
the creation of a global system for distributing and
controlling the sale of diamonds.
The Harry Oppenheimer House is a
darkly tinted glass skyscraper that stands in a private
park in the center of Kimberley. Built in 1974, the
entire building was designed and dedicated to a single
purpose: the evaluation of uncut diamonds. The entire
total of all the diamond mines and diggings in South
Africa and Namibia are shipped here to be sorted, classified
and valued. The diamond consignments generally arrive
early in the morning in armored trucks, which drive
into a concrete bunker in the sub basement of the building.
The sealed containers of diamonds are then sent in a
special elevator, which makes no intermediary stops,
to the top floor. The seal is broken in front of witnesses,
and the diamonds immersed in an acid bath to clean off
any particles of dirt. After the diamonds are dried
by hot-air jets, they are weighed on a highly precise
electronic scale. This weight is then entered into a
central computer, which will track the shipment as it
moves through each stage in the sorting process.
If at any point the weight of the
categories it has been divided into adds up to less
than the original weight of the consignment, the computer
sets off an alarm. This automatically locks the doors
of the Harry Oppenheimer House. Only when the missing
weight of diamonds is found will the computer permit
anyone to leave the building.
Unlike gold or other precious metals,
diamonds cannot be assigned a value merely by weighing
them. An ounce of diamonds can be worth $100 or $100,000
depending on the quality of the diamonds. Before either
a mine-or the South African tax authorities-can determine
the value of the diamonds, they have to be sorted into
their proper size, shape, color and clarity categories.
"By the time we finish, a shipment is broken down into
some two thousand different categories. The preliminary
sorting is done by a series of ingenious machines that
De Beers engineers invented specifically for this purpose.
First, the diamonds are passed through a series of sieves.
Diamonds that are too small to be cut into jewels are
screened out as industrial diamonds. The remaining diamonds
are then divided into sixteen different groups according
to sizes that range from under to-tenths of carat to
over one carat.
Next, within each group, the diamonds
are sorted for shape by a series of machines, which
by vibrating and twisting are able to separate flat
and triangular shapes from the more valuable tetrahedral-shaped
diamonds. At each stage in the separation process, the
resulting groups are weighed and registered into the
Finally, in this rough sorting, the
diamonds are fed into a series of X-ray machines, which
by employing different filters are able to automatically
sort the diamonds into different colors. The opaque
and black diamonds, called bort, as well as the smaller
brown and golden diamonds, are separated out to be crushed
into industrial abrasives. The diamonds are then again
reweighed and sent to the floor below for hand sorting.
Here the gem-grade diamonds are
laid out by colors on separate tables, which have been
perfectly positioned in respect to the light. A team
of sorters,. women in uniformly colored dresses and
men in suits, then examine each diamond with a six-power
jewelers' loupe to make sure that it is correctly classified.
If any of the five sorters disagrees in their opinion,
the chief sorter, John Gie, is called in to arbitrate
and make a final decision on that particular diamond.
"These are all highly skilled and
trained quality controllers," Gie explained to me. All
are given periodic eye examinations by De Beers and
are tested on their ability to match unsorted diamonds
to the De Beers sample set. This set contains some 240
different shades of colors and shapes which serve as
a De Beers standard for sorting operations in both Kimberley
and London. After every gem diamond is checked for microscopic
imperfections representatives of the Diamond Producers
Association, which represents individual producers as
well as the De Beers-owned mines, are allowed to question
any classification they disagree with. In fact this
generally is nothing more than a formality.
"A single diamond can be examined
as many as ten times," observed Gie. When everyone has
agreed on the proper classification of each diamond,
the data is fed into the computer. As each diamond is
finally weighed, the computer assigns a dollar value
to it according to a complex formula. The computer then
instantly tallies up the total value of the shipment
and credits that amount to the account of the individual
A small percentage of these sorted
diamonds are retained at Harry Oppenheimer House and
distributed to a select number of local South African
dealers. All the rest of the diamonds of South Africa
and Namibia are shipped in sealed containers by air
to the Diamond Trading Company's headquarters in London.
These consignments from Kimberley amounted to some 5,400,000
carats and accounted for about half of all the gem diamonds
shipped to London.
I next followed the trail of diamonds
from the sorting house in Kimberley to the Diamond Trading
Company in London. The trip to the African mines had
explained how diamonds were extracted from the earth,
but this was only a rudimentary part of the diamond
invention. The crucial element in the invention was
controlling the supply available to the major diamond
cutters and manufacturers, and this allocation took
place in London.