The Williamson Diamond Mine (also known as the Mwadui mine) is a
diamond mine
There are a limited number of commercially available diamond mines currently operating in the world, with the 50 largest mines accounting for approximately 90% of global supply. Diamonds are also mined alluvially over disperse areas, where dia ...
northeast of
Shinyanga
Shinyanga, also known as Shinyanga Mji in the local Swahili language, is a city in northern Tanzania. The city is the location of the regional headquarters of Shinyanga Region as well as the district headquarters of Shinyanga Urban District. The ...
in
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...
; it became well known as the first significant diamond mine outside of
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
. The mine was established in 1940 by Dr.
John Williamson, a
Canadian
Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...
geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
,
and has been continuous operation since then, making it one of the oldest continuously operating diamond mines in the world. Over its lifetime it has produced over 19 million
carats (3,800 kg) of diamonds. A 2020 report by ''The Guardian'' said that high-quality pink diamonds from the mine could value up to $700,000 a carat.
The Williamson mine was once owned by its namesake Dr. Williamson and later
nationalized
Nationalization (nationalisation in British English) is the process of transforming privately-owned assets into public assets by bringing them under the public ownership of a national government or state. Nationalization usually refers to pri ...
by the government of Tanzania. Since February 2009 the mine is mostly owned by
Petra Diamonds
Petra Diamonds Ltd is a diamond mining group headquartered in Jersey. Petra own one of the world's most productive mines historically, the Premier Mine, Cullinan Diamond Mine is famed for having produced the Cullinan Diamond, world's largest roug ...
, with 75% ownership, the government of Tanzania owning the remaining 25%. In 2020, the mine came under scrutiny because of alleged human rights violations.
Description
The Williamson diamond mine is a large
open pit
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow.
This form of mining ...
mine currently about 90 meters (300 ft) deep. Diamond mining operations at the Williamson diamond mine are composed of four distinct activities: mining of the pit, re-treatment of
tailings
In mining, tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different to overburden, which is the waste rock or other material that overlie ...
to recover missed diamonds, and
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
mining both on the property and adjacent to the property where gravel has been
alluvially deposited. The open pit mining and tailings re-treatment are the largest of the four operations. The mine employs about 1,100 staff, mostly Tanzanians.
Location
The mine is located about south of the town of
Mwanza
Mwanza City, also known as Rock City to the residents, is a port city and capital of Mwanza Region on the southern shore of Lake Victoria in north-western Tanzania. With an urban population of 1,182,000 in 2021, it is Tanzania's second largest cit ...
in
Kishapu District
Kishapu District is one of the three districts of the Shinyanga Region of Tanzania. It is bordered to the north by the Maswa District, to the south by the Tabora Region, to the east by the Meatu District and to the west by the Shinyanga Rural and ...
of
Shinyanga Region
__NOTOC__
Shinyanga Region (''Mkoa wa Shinyanga'' in Swahili) is one of Tanzania's 31 administrative regions. The regional capital is the municipality of Shinyanga.
The region is bordered to the north by the Mwanza, Mara, and Kagera Regio ...
. Dr. Williamson, the discoverer of the site, first owner and namesake of the mine, named the site "Mwadui" after a local chief; "Williamson" and "Mwadui" are now virtually synonymous in the diamond mining world.
Geology
The most important geological feature of the Williamson diamond mine is the
kimberlite pipe
Volcanic pipes or volcanic conduits are subterranean geology, geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of ''diatreme''. Volcanic pipes are composed of a deep, narro ...
on which it is located. At 146 hectare in area at surface level, it ranks as the largest economically exploitable diamond-bearing volcanic pipe in the world. Recent exploratory drill cores conducted by De Beers have indicated that the pipe is a
pyroclastic
Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...
kimberlite, not a
hypabyssal A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneous rock that is emplaced at depths less than within the crust, and has intermediate grain size and often porphyritic texture between that of volcanic rocks and plutonic roc ...
kimberlite as earlier suspected. This indicates that it may be possible to extend the current 90-meter deep open pit to as much as 350 meters deep, and continue down even further with underground mining operations. However, a review of mine operations and long term plans continues.
Production
The Williamson diamond mine is now characterized by low
ore grade
Ore is natural Rock (geology), rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Ret ...
of about per hundred tons (12 mg/t) of
ore
Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 April 2 ...
. This is a dramatic decrease from its production in the mine's early life; during the first 25 years of operation, average ore grade was about per hundred tons (60 mg/t); in the first few years of full operation grades were as high as per hundred tons (124 mg/t), or 10 times the ore realized today. Production in the 1950s and 1960s was usually between 500,000 and 750,000 carats (100 and 150 kg) per year; the peak year of production was 1966, when 924,984 carats (185 kg) were produced. Today production levels for all Williamson mine diamond recovery activities is about 300,000 carats (60 kg) per year.
Notable stones produced at the Williamson mine include the
Williamson pink diamond
The Williamson pink diamond is a flawless pink diamond discovered at the Williamson diamond mine in Tanganyika in 1947. The owner of the mine, Canadian geologist John Williamson gave the uncut stone to Princess Elizabeth and Prince Philip upo ...
which was presented to then-
Princess Elizabeth and
Prince Philip
Prince Philip, Duke of Edinburgh (born Prince Philip of Greece and Denmark, later Philip Mountbatten; 10 June 1921 – 9 April 2021) was the husband of Queen Elizabeth II. As such, he served as the consort of the British monarch from E ...
upon their wedding in 1947,
[ and a diamond found in 1990.
]
History
The diamond industry
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, b ...
of Tanzania in the 1930s was characterized by a scattering of very small mining operations that were insignificant in the economic makeup of the country. Dr. Williamson was hired by one of these operations, the Mabuki diamond mine, in 1938 and used it as his base for diamond prospecting
Prospecting is the first stage of the geological analysis (followed by exploration) of a territory. It is the search for minerals, fossils, precious metals, or mineral specimens. It is also known as fossicking.
Traditionally prospecting reli ...
in the region. In 1940 he discovered the Mwadui kimberlite pipe;[ over the next several years he developed the mine, although he was hindered by difficulty in procuring equipment and raising funds due to ]World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. By the 1950s he had developed the Williamson diamond mine into the first significant diamond mine in Tanzania. The mine was visited in the early 1950s by the US author John Gunther
John Gunther (August 30, 1901 – May 29, 1970) was an American journalist and writer.
His success came primarily by a series of popular sociopolitical works, known as the "Inside" books (1936–1972), including the best-selling '' Insi ...
who describes it in his book ''Inside Africa''. The mine then employed 2,600 African workers, 110 Europeans and 60 Asians. The mine was noted for technical innovations in diamond mining which were developed under Williamson's watch. Williamson closely managed the mine until his death in 1958 at the age of 50.
Williamson's heirs sold the mine[ for about £4 million ]GBP
Sterling (abbreviation: stg; Other spelling styles, such as STG and Stg, are also seen. ISO code: GBP) is the currency of the United Kingdom and nine of its associated territories. The pound ( sign: £) is the main unit of sterling, and t ...
to an equal partnership between De Beers
De Beers Group is an international corporation that specializes in diamond mining, diamond exploitation, diamond retail, diamond trading and industrial diamond manufacturing sectors. The company is active in open-pit, large-scale alluvial and c ...
and the colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 au ...
government of Tanganyika
Tanganyika may refer to:
Places
* Tanganyika Territory (1916–1961), a former British territory which preceded the sovereign state
* Tanganyika (1961–1964), a sovereign state, comprising the mainland part of present-day Tanzania
* Tanzania Main ...
on August 13, 1958. In 1971, a decade after Tanzania's independence, the government nationalized the mine. Although details are unknown, De Beers and other diamond industry players speculate that mine performance deteriorated significantly in the 1980s under government management. Suspected causes of this are a decrease in ore grade as the mine's richer deposits were worked out, loss of skilled foreign management and engineering staff, a bloated labor force resulting from government employment efforts, and inadequate capital investment
Investment is the dedication of money to purchase of an asset to attain an increase in value over a period of time. Investment requires a sacrifice of some present asset, such as time, money, or effort.
In finance, the purpose of investing is ...
in the mine's equipment. Perhaps as a result of this poor performance, Tanzania invited De Beers to purchase back into the mine, which the company did. In 1994 De Beers bought 75% of the Williamson mine, with Tanzania retaining the remaining shares.
Since 1994, De Beers has acted to improve the performance of the Williamson diamond mine by trimming the work force, making capital investment in equipment, and bringing in expertise in technology, technique, and exploration. Although the mine is still viewed as a marginal performer due to its low ore grade, De Beers has identified avenues for development that would keep the mine operating into the future.
In September 2008, Petra Diamonds Ltd agreed to acquire the Williamson Mine from De Beers and completed the acquisition in February 2009.
In April 2020, the mine was mothballed after the collapse of diamond prices.
Although in February 2021 Petra & the Tanzanian Government entered discussions to reopen the mine in Q4 2021, but that did not happen.
In September 2021 Petra announced that it was seeking a buyer for the mine. Confirming news reports from March, when the company prospectus described the mine as permanently closed.
Recreation
The mine was equipped with a range of sporting facilities. These included public swimming pool, tennis and squash courts, soccer field, athletics track, golf course and yacht club. There was also a surgical hospital staffed by two English and an Indian doctor and nursing staff. The hospital used to treat the mine employees for free, and poor people from neighbouring areas could take treatment there at nominal charges. These facilities fell into disrepair after the colonial era, but remain partly maintained by the mine.
Incidents
2020 human rights allegations
A lawsuit against for human rights violations by guards was filed in May 2020 in the High Court of England and Wales
The High Court of Justice in London, known properly as His Majesty's High Court of Justice in England, together with the Court of Appeal and the Crown Court, are the Senior Courts of England and Wales. Its name is abbreviated as EWHC (England ...
. NGO RAID claimed evidence of harm by contracted guards who shot locals on the concession, including 10 killings and 50 injuries since 2009. Following the report, Petra Diamon initiated an internal investigation. Initial internal investigations found record of only one live-fire incident during the alleged window, alongside other use of "reasonable force" against illegal miners.
References
Sources
* Tassell, Arthur. ''African Mining Magazine''
"Williamson – A Bright Future Ahead?"
Brooke Pattrick Publications.
* De Beers Group official website
"De Beers Group: Tanzania"
Retrieved April 18, 2005.
* {{cite journal, last1 =Knight, first1= John , last2 = Stevenson, first2= Heather, title = The Williamson Diamond Mine, De Beers, and the Colonial Office: A Case-Study of the Quest for Control, journal = Journal of Modern African Studies, publisher = Cambridge University Press, volume = 24, number= 3 , date = September 1986, pages =423–445, jstor= 160350
* Chopra, Jarat. "Tanganyika Diamond Presented to Princess Elizabeth," ''Old Africa'', No. 21 (February–March 2009) 16–17.
* Chopra, Jarat. "Princess Margaret Hosted in Mwanza," ''Old Africa'', No. 22 (April–May 2009) 20–22.
Diamond mines in Tanzania
Surface mines in Tanzania
Diatremes
Volcanoes of Tanzania
Pre-Holocene volcanoes
1940 establishments in Tanganyika