Diamonds are found in Australia, Botswana, Canada, Namibia, Russia, Sierra Leone, South Africa, Brazil, Venezuela, China, India, Indonesia, the Central African Republic, D.R. Congo, Guyana, Ghana, Guinea, the Ivory Coast, Liberia, Tanzania, - PowerPoint PPT Presentation


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Diamonds are found in Australia, Botswana, Canada, Namibia, Russia, Sierra Leone, South Africa, Brazil, Venezuela, China, India, Indonesia, the Central African Republic, D.R. Congo, Guyana, Ghana, Guinea, the Ivory Coast, Liberia, Tanzania,


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Title: Diamonds are found in Australia, Botswana, Canada, Namibia, Russia, Sierra Leone, South Africa, Brazil, Venezuela, China, India, Indonesia, the Central African Republic, D.R. Congo, Guyana, Ghana, Guinea, the Ivory Coast, Liberia, Tanzania,

Diamonds are found in Australia, Botswana,
Canada, Namibia, Russia, Sierra Leone, South
Africa, Brazil, Venezuela, China, India,
Indonesia, the Central African Republic, D.R.
Congo, Guyana, Ghana, Guinea, the Ivory
Coast, Liberia, Tanzania, and Zimbabwe.
Only 20 of the diamonds mined are suitable for
polishing, and about 80 are industrial qualities
which are used in the medical field, in the space
programs, and for industrial diamond tools
amongst other things.
Types of Diamond Deposits
Geologic processes create two basic types of
diamond deposits, referred to as primary and
secondary sources. Primary sources are the
kimberlite and lamproite pipes that raise
diamonds from Earth's mantle, where they
originate. Secondary sources, created by erosion,
include such deposits as surface scatterings
around a pipe, concentrations in river channels,
and fluxes from rivers moved by wave action along
ocean coasts, past and present. Mining of these
deposits depends upon sufficient concentration
and quality of diamonds.
India was the only source of diamond until
1725. In 1725, Brazil diamond deposits (Minas
Gerais and Bahia) were discovered and were used
for about 150 years. In 1866, diamonds were
discovered in the gravels of the Vaal River,
South Africa.. The United States has produced a
few diamonds .The well-known U.S. diamond deposit
is at Crater of Diamonds State Park in
Murfreesboro, Arkansas. The largest U.S. diamond,
the "Uncle Sam" which weighs 40.23ct, came from
this site. In late 1991, of a diamond-bearing
kimberlite of apparent economic potential at
Point Lake, near Lac de Gras in the Northwest
Territories, At present, Argyle diamond deposits
(discovered in 1979), W.Australia has been the
major diamond deposit since 1986 (1/3 world
production annually).
Distribution of World Diamond Deposits
(No Transcript)
Occurrences Where cratonic areas Assoc. rocks
Kimberlites or
Lamproites Diamond deposits Primary in
diamond pipes Secondary in sediments Diamond
mining Onshore surface/underground Offshore
sea bed
Schematic model of a fully grown kimberlite pipe
(No Transcript)
(No Transcript)
Formation of a diamond pipe
Inclusions as indicator of the origin of diamonds
a.) A purple pyrope garnet, an indicator of
garnet harzbugite , Udachnaya pipe,
Russia. b.) Orange garnet, typical of diamond
eclogite. c.) Red Cr pyrope and green Cr
diopside indicators of a peridotite,
Mir pipe, Russia.
Cones and cyclones use swirling heavy fluids
mixed with crushed ore to achieve density
separations. With 99 percent of the waste in the
ore removed, further separations may use either a
grease table or an x-ray separator. Final
separation and sorting is done by eye.
The x-ray separator system acts on a thin stream
of particles from the concentrate accelerated off
a moving belt into the air, where they encounter
an intense beam of x-rays. Any diamond fluoresces
in the x-rays, activating a photomultiplier that
triggers a jet of air, deflecting the diamonds
(blue) into a collector bin. Adapted from Bruton
  • Africa
  • South Africa
  • Namibia
  • Botswana
  • North America
  • Canada
  • USA
  • Australia
  • Western Australia
  • Eurasia
  • Russia
  • India
  • Southeast Asia

Diamond Mining is undergoing a resurgence with
several African Mining Companies operating major
mines. De Beers in South Africa Debswana in
Botswana, Miba in the Congo and Namdeb in Namibia
are the major African Producers. A large number
of diamonds are being hand mined by locals and
sold to buyers. In Australia, Ashton Mining are
continuing with AK1 pipe in the Kimberley as an
open cut operation and are opening new diamond
mines at Cempaka in Kalimantan, Indonesia and
Merlin in NT, Australia. The Cempaka alluvial
deposits are mined with dredges. Merlin is open
cut with several diamondiferous kimberlite pipes.
BHP is continuing mining the Ekati Deposit in
Canada. ( http//
Table I Estimated 1999 Diamond Production by
Country Carats (000) Value ( m)
Botswana 21,348 1,612
Russia 16,200
1,523 South Africa 9,733
985 D.R. Congo 22,000
725 Angola 3,625
544 Australia
29,784 437 Canada
2,510 422 Namibia
1,611 413 Sierra Leone
600 138 Guinea
550 120 Central
Africa Rep 450 92
Country Carats (000) Value (
m)Venezuela 450 58
Brazil 900
41 Tanzania 232
37 Liberia 200
32 Ivory Coast 165
24 Ghana 500
19 China 146
15 Lesotho 43
15 Guyana 11
1 Total 111,058
Source Mining Journal, London, June 16, 2000
Africa is the richest continent for diamond
mining, accounting for roughly 49 of world
production. The major sources are in the south
with lesser concentrations in the west-central
part of the continent. The major producing
countries are Congo Republic (Zaire), Botswana,
South Africa, Angola, Namibia, Ghana, Central
African Republic, Guinea, Sierra Leone, and
Zimbabwe. Political turmoil in some countries
has led to highly variable production and severe
degradation of the environment from uncontrolled
Primary Deposits D.R. Congo (19.81), Botswana
(19.22), South Africa (8.76), and Angola(3.26
) Secondary Deposits Onshore Angola and South
Africa Offshore South Africa and Namibia
Other African producers and their percentage of
world production in 1999 Central African Republic
0.40 Ghana 0.45 Guinea 0.50 Ivory Coast
0.15 Lesotho 0.04 Sierra Leone 0.54 Tanzania
Source Mining Jour., June 16, 2000
Diamond Deposits of Orange River Valley
Diamonds have been transported across the vast
area of southern Africa shown on this map. There
are more than 3,000 kimberlite pipes -- many not
bearing diamonds, of course -- in the craton
drained by tributaries to the Orange River and
its precursors, which end at the Atlantic coast.
The rivers carried water, sediments, and diamonds
to the ocean.
Alluvial mining of diamond deposits.
  • South African Production Total 520 million
    carats Annual 1870 269,000 carats 1903 3
    million carats Today 8 to 10 million carats
  • 9.73 million carats in 1999
  • Onshore and offshore deposits
  • De Beerss and Southern Era Co.

Could be a scene from the cold war, but its
actually the security fenceline to a South
African diamond mine.
The Venetia diamond mine, which opened in 1992,
represents one of De Beers largest single
investments in South Africa. Situated 80 km from
Messina in the Northern Province, and involving
an investment of R1.1 billion (US400 million)
the mine is South Africas largest diamond
producer, with an output of 4.3 Mct from 3.4 Mt
of ore in 1997, and 4.5 Mct in 1998. It employs
about 700 people.
Scenes from Venetia Mine
Can't quite understand the meaning of this sign
at the Venetia diamond mine but it seems funny
A bank of four x-ray machines sorts the precious
diamond from waste material
Kimberley Mine in 1873
From "The Diamond Mines of South Africa," G.F.
Williams, New York, 1906.
Barney Barnato
Cecil John Rhodes
Kimberley Mine, the Big Hole on Earth, today.
Premier Mine, home of the 3106 carat Cullinan
A cross section of the underground workings at
the Dutoitspan mine, Kimberley, South Africa.
Adapted from De Beers
  • Part of an extremely old region, with gt 2.0 Ga.
    basement rocks.
  • The basement rocks are usually covered by
    Mesozoic sediments.
  • Tectonic activity over the last 100 Ma. or so
    created a number of
  • rifts and the uplifting of most of the area
    above sea level.

Onshore mining in Namibia has produced 70 million
carats since the first diamond rush in 1908.
Namibias diamonds derive not from primary
kimberlite pipes, but from secondary diamond
deposits areas where diamonds have been washed
down and deposited by old rivers, which have
eroded kimberlite pipes in the interior on their
In the early days, from 1908 to 1910, diamonds
were recovered from the coastal sands in Namibia
by workerscrawling on hands and knees.
In 1908 a railroad worker found diamonds in the
sand dunes near Kolmanskop, South West Africa
(now Namibia), then a German colony. In 1909
almost 500,000 carats were produced there, and
yields almost tripled in 5 years. The diamonds
were small but of high quality. South Africa
gained control of Namibia after World War I and
sold the diamond deposits to Consolidated Diamond
Mines (CDM), which was transferred to De Beers in
1929. In 1994 CDM was reconstituted as Namdeb
Diamond Corporation Limited and is now jointly
owned by the Namibian government and De Beers.
The production, 1,300,000 carats in 1995, is from
beach deposits.
  • A Texan named Sammy Collins drew worldwide
    attention in 1962 announced the discovery of
    50,000 carats of diamonds worth 1.5 million from
    the seabed of the Diamond Coast of South West
  • The diamonds were carried there by the Vaal and
    Orange rivers from some far inland deposit, they
    also ought to be found under the ocean.
  • Over a period of three years, Collins used the
    equivalent of huge vacuum sweepers to suck some
    400,000 carats of diamonds from the seabed.
  • Today, with improved technology, De Beers and
    others are once again probing the waters of the
    South Atlantic, bringing closer the prospect of
    viable undersea diamond recovery in the 1990's.

There are 3 types of marine mining operations. In
one, sand is moved from 10 meters below sea level
to as far inland as the sea may have risen, in
order to reveal the concentrations on the
bedrock. In another, divers and boats work in the
surf zone to perhaps 20 meters of water and use
suction pipes to remove gravel and diamonds from
the ocean floor. In the third, deep-sea marine
vessels use remote underwater tractors or large
underwater excavators to remove overlying
sediments and extract the diamond-bearing sand
and gravel. Processing is done on land in the
first 2 cases and shipboard on the large mining
Suction pipes used to pump diamond-bearing gravel
are being moved into the surf by divers at
DePunt, South Africa.
Because powerful ocean waves break the poorer
quality diamonds, 90-95 percent of marine
diamonds are of gem quality. The littoral zone,
the area of wave action on the Atlantic coast
where diamonds accumulate, has moved in and out
with changes in sea level, but shore lines have
been constant over long periods, resulting in
wave-cut terraces with hollows and crevices in
which diamonds concentrated. These terraces are
preserved hundreds of meters both above and below
sea level and are the focus of mining activity.
The mining vessel "Geomaster" of the De Beers
Marine fleet working off the coasts of Namibia
and Namaqualand, South Africa. It is capable of
operating in depths up to 200 m (660 feet).
Massive sand walls keep back the sea during
mining of diamond-bearing terraces in the
foreshore. Consolidated Diamond Mines (now
Namdeb) has successfully employed this
engineering technique in Namibia.
After removal of many meters of Kalahari sands
from the bedrock surface on Namibia's west coast,
workers scour exposed crevices and crannies for
(No Transcript)
Botswana's mining minister K. Moshashane, said
that diamonds (70 of his country's
earnings)"have transformed Botswana from dire
poverty into a stable democratic developing
country. Nicky Oppenheimer, the Chairman of De
Beers Consolidated Mines Ltd., stated, "Since the
discovery of its diamond deposits, Botswana has
achieved record economic growth."
Ref. http//
De Beers discovered 3 world-class kimberlite
deposits in Botswana between 1967 and 1973. The
Orapa pipe, found in 1967, is the second largest
economic kimberlite pipe in the world and
produces about 5.5 million carats annually. The
Jwaneng pipe was discovered in 1973 under the
sands of the Kalahari Desert. With over 10
million carats produced in 1995, it was the
second most productive mine for weight of
diamonds but first for currency value. Two
smaller pipes, Letlhakane 1 and 2, were
discovered in 1968. Botswana's diamond reserves
are immense.
The Orapa Mine has been in production since 1971
and is the second biggest mine in Botswana,
currently producing more than 6 million carats
per annum, worth over 400 million. An expansion
to the mine, due for completion in 2000, will
double capacity to 12 million carats per annum.
The Jwaneng mine, in Botswana, is the most
valuable diamond mine in the world. Its 1995
production of about 10.5 million carats had a
value of about 1.2 billion.
Congo Republic (Zaire)
With 19.8 of world production, this is the
second largest producer of diamonds by weight (22
million carats in 1999) after Australia. Only 6
is of high gem quality another 40 consists of
small stones, called near-gem, that are cut in
India. Mbuji-Mayi is one of the world's most
prolific mines. In recent years production has
been about 5 million carats per year.
  • W.Australia , New South Wales,
  • Queensland
  • Kimberley regions (Ellendale
  • and Argyle areas)
  • Argyle AK-1 and Bow River
  • deposits are most productive
  • 29.7 million carats in 1999

Argyle diamond mine, Western Australia and its
In 1979, a large lamproite pipe was found and
named the Argyle mine by 1992 over 200 million
carats had been mined there. Only 5 of the
production is gem quality. A unique feature of
the Argyle mine, though, is a small but
consistent supply of valuable pink to red or
purple diamonds.
Argyle Diamond Pipe
The Argyle diamond pipe is in a small valley at
the southend of the Matsu Range. The pipe is
about 2 km long by 150-500 m wide and
steep-sided. The shape of the pipe has been
modified by faulting. In this photo, the dirt
road runs on the pipe along the valley floor.
The most common rocks are quartz-rich lapilli
ash tuffs
Cross-section of the Argyle diatreme from Boxer
and others (1989).
Intrusive olivine lamproite dikes and
fine-grained quartz-rich sediments
Most of the diamonds at Argyle are resorbed
A small percent of the diamonds from Argyle are
sharp-edged octahedra with hexagonal surface
Diamond deposits of North America
Near Murfreesboro, Arkansas, from what is now
known to be a lamproite pipe, more than 100,000
stones averaging 0.25 carat each were produced
between 1907 and 1933. Now Crater of Diamonds
State Park, the locality is a stop for hobbyists
and tourists. The "State Line Kimberlite
District" along the Colorado-Wyoming border is
home to the only operating diamond mine in the
U.S., started at Kelsey Lake, Colorado, in June
1996. The largest diamond found so far is 28.3
carats, and about 25 of the 20,000-carat annual
production is of gem quality.
Excavation of the Kelsey Lake 1 kimberlite,
which began mining in June, 1996.
  • Crater Of Diamonds State Park
  • Arkansas, USA
  • Southwest Arkansas near Murfreesboro is a rare
    35-acre field where
  • diamonds can be found in their natural matrix.
  • The only diiamond area in North America open to
    the public.
  • Over 70,000 diamonds found at the "Crater" (an
    eroded volcanic pipe).
  • The big finds are the Uncle Sam (40.23 carats),
    Star of Murfreesboro
  • (34.25 carats), Star of Arkansas (15.33
    carats), and the Ama-rillo Starlight
  • (16.37 carats).
  • An average of more than 600 diamonds are found
    each year.
  • Amethyst, agate, jasper, quartz, calcite, barite
    and many others,
  • including over 40 different rocks and minerals,
    make the area
  • a rock-hound's delight.

Anyone can search for diamonds at the Crater of
Diamonds State Park, Murfreesboro, Arkansas.
17 carat Arkansas diamond crystal from Pike
County from the Roebling collection in the US
National Museum (Smithsonian).
Intermittent exploration for kimberlites by major
companies was unsuccessful through the 1980s. But
Chuck Fipke, head of Dia Met Minerals, persevered
and in April 1990 located a kimberlite under
Point Lake. Eventually, his company, with partner
BHP Minerals, found more than 100 kimberlites on
their claims 42 contain diamonds. Five small
pipes, to be operated as if they were one mine,
are scheduled to start production in the second
half of 1998.
The first kimberlite pipe discovered in the
Northwest Territories is under Point Lake. The
top of the kimberlite lies about 50 m below the
surface of the lake, which is 600 m wide.
(No Transcript)
By 1985, after collecting diamond-indicating soil
samples for nearly a decade, Canadian geologist
Charles Fipke had followed a trail of kimberlitic
minerals (those left on the earth's surface in
the aftermath of kimberlite volcanoes) to the Lac
de Gras region of the Northwest Territories. Six
years later, with the help of an enthusiastic new
partner, BHP Minerals, Fipke and his crew
discovered the area's first ancient kimberlite
volcano or "pipe" under Point Lake. In the fall
of 1991, they recovered 81 diamonds from a 58
kilogram core sample and triggered the largest
staking rush in Canadian mining history.
BHP Diamond Inc. and DiaMet joint
venture http//
A total of 121 kimberlite "pipes" have been
discovered in the Ekati claim area.
The only source of diamonds until 1725 Total
production 21 million carats Maximum annual
50,000 to 100,000 carats in late 1600s Today
20,000 carats
Diamonds were discovered in India by the 4th
century BCE. In addition to the diamond legends,
India yielded many legendary diamonds, including
the Koh-i-Noor, the Orlov, the Hope, and the
Sancy. Except for a minor supply of diamonds from
the Kalamantian deposits of Borneo, dating from
the 6th century CE, India was the world's only
source until the 1730s. Most of India's deposits
were alluvial, but today the Majhgawan pipe, a
primary source near Panna, is the country's only
producing diamond source.
The history of the stone which was eventually
named the Hope diamond was most likely from the
Kollur mine in Golconda, India. Its color was
described by Tavernier as a "beautiful violet."
Golconda is often cited as a mine source for
Indian diamonds, but this ancient capital city
was a trading center the Kollur deposits are
Workers remove diamond-bearing gravel under the
watchful eye of an overseer in diamond mines near
Panna. Valentine Ball. "A manual of the geology
of India." Calcutta 1879-1887.
Diamond Washing in The Raolconda Mines. A
historic representation of diamond mining in
India, printed in 1859.
The five major historical diamond producing
regions of India are shown here. These were
mostly alluvial deposits in river channels. Only
the Majhgawan lamproite pipe, near Panna, is now
in operation.
  • In the 1930s, academician Vladimir S. Sobolev
    recognized similarities between the ancient
  • bedrock of Siberia and that of South Africa and
  • In 1947, prospecting started by looking in
    streambeds for trails of indicator minerals.
  • In 1954 in Sakha (formerly Yakutia), the first
    kimberlite pipe, Zarnista (Dawn) was found in the
  • Daldyn field.
  • n 1955, the very rich Mir (Peace) and Udachnaya
    (Lucky) pipes were discovered .
  • By 1956, more than 500 kimberlites had been
  • By 1970 Russia had become the third largest
  • Its production is about one quarter gem
    diamonds, worth 1.2 billion, second to Botswana.

The Yakutia Craton in eastern Siberia is the
world's second most productive craton. Only the
Anabar Shield and Aldan Shield portions are
exposed the rest is covered with sedimentary
rocks into which the kimberlite pipes have
The main producing kimberlite areas are the
Daldyn and Alakit fields (A) and the Malaya
Botuobiya field (B). Important pipes that are
producing or may produce are named.
The Internationalnaya mine, only 40 km from the
Mir (Peace) pipe, has terminated above ground
operations, and underground operations have been
hampered by waters that emit toxic gases.
The Mir mine in the Malaya Botuobiya field was
the first Russian mine opened in 1957. Annual
production has averaged about 2 million carats.
Although the pipe has been mined out, stockpiles
and tailings (waste) continue to be worked for
Blasting to dislodge hard kimberlite at the
Udachnaya mine, the most productive one in the
Sakha Republic.
The open pit at the Udachnaya (Lucky) pipe in
Sakha Republic, Russia, has produced many
millions of carats of diamond. The bench steps
are about 20 m high.
Inclusions of garnet and sulphides in octahedral
diamond from the Udachnaya pipe
The group of sulphides in octahedral diamond
General Location Map Western Europe, NW Russia
Russian Production Total 332 million carats
Annual in 1970 7.5 mil. carats Today 10-12.5
million carats
Grib Diamond Pipe Artist's Three Dimensional View
Looking Southwest Scale About 1"(2.54 cm) equals
500 meters (1,640 feet)
When diamonds were discovered by alluvial gold
miners in Brazil in 1725, Indian diamond sources
were near exhaustion and European demand for the
stone continued unabated. From 1730 to 1870
Brazil was the world's major source of diamonds.
Indeed, mining in Brazil was so active that by
the late 1730s production far exceeded demand,
and diamond prices fell by as much as 70.
Beginning in 1850, production rose again,
following the discovery of rich deposits in
Bahia, but after 1861 it rapidly declined as
deposits were depleted, leading to a great
shortage of rough diamonds in the European
cutting centers in the late 1860s.
Productive Brazilian diamond deposits are all
secondary. They are usually small, and some are
of low grade, so mines typically operate for
short periods. Primary diamond pipes exist but
are generally uneconomic, suggesting that erosion
has stripped away the richest portions from them.
In 1890 and 1901, secondary diamond deposits were
discovered in Guyana and eastern Venezuela,
adjacent to deposits in Brazil's northern state
of Roraima. Since 1890, Guyana and Venezuela have
produced a total of about 4.5 and 14 million
carats, respectively.
Diamond mining in Brazil
"A view of the manner in which the bed of the
river is laid dry by an aqueduct." From John
Mawe, "Travels in the interior of Brazil."
London 1812.
"View of Negroes washing diamonds at Mandango."
From John Mawe, "Travels in the interior of
Brazil." London 1812.
Diamond deposits are widely distributed in
Brazil. Those in the states of Minas Gerais,
Bahia, Mato Grosso, and Rorama have been the
most important. The shaded areas are diamond
Brazilian Production Total 55 million carats
Old annual 50,000 to 300,000 carats 1730s to
1861 Today 1.5 million carats
Myanmar Momeik, Theindaw and Taungoo-Htantabin
areas Thailand Phuket-Takua Pa area Indonesia
Sumatra and Kalimantan areas
  • Griffin,W.L., Win,T.T.,Davies, R., Wathanakul,
    P., Andrew, A., and Metcalfe, I, 1998.
    Diamonds from Myanmar and Thailand
    characteristics and possible origin
  • Spencer, L. K., Dikinis, S. D., Keller, P. C.,
    and Kane, R. E. (1988). "The diamond deposits of
    Kalimantan, Borneo". Gems Gemology 24 67-80.

Distribution of alluvial diamonds in SE Asia.
Sibumasu terrane outlined by thick dashed line.
Inset Permian plate reconstruction, showing
location of Sibumasu (S) and Western Burma (WB)
terranes adjacent to NW Australia.
Carbon-isotopic composition of diamonds from
Myanmar and Thailand, compared to diamonds from
Argyle and eastern Australia. .
The Southeast Kalimantan diamond fields are
emerging as having potential to host large, long
life alluvial diamond deposits. Indomins diamond
projects in South Kalimantan are at an advanced
stage with bulk testing programs underway in both
the onshore Martapura project (Indomin 60) and
the shallow offshore Sunda Shelf project (Indomin
21 financed to production and Trans Hex
International 30 and operator). Adjoining the
Martapura project, Ashton Mining of Australia has
commissioned the construction of a dredge for
diamond production from their Cempaka-Danau Seran
diamond project. The bulk testing programs
underway at Indomins Martapura project will
determine the grade of diamondiferous gravels
already outlined. If an economic grade is defined
the project will then move to a feasibility study
for diamond mining which, if positive, would make
the project a potential company maker.
http// (
October 2000)
It looks like muddy, unpleasant work and it may
well be but the rewards are diamonds and a chance
for wealth. Work in these fields, at Cempaka in
Kalimantan, is handed down from generation to