Cecil Rhodes De Beers: Origins, Cullinan, Venetia

Cecil Rhodes founded De Beers Consolidated Mines in 1888 by joining his diamond interests with those of Barney Barnato; Rhodes chaired the company until 1902 (De Beers Group, company history). He died on 26 March 1902, before the Premier mine near Pretoria, now called Cullinan, was even found. The two mines in this guide’s title are not part of the Rhodes story in the way many pages suggest: Cullinan is run today by Petra Diamonds, and Venetia opened in 1992, ninety years after Rhodes died.

This guide follows the story in order. It covers how Rhodes built the company, what the Cullinan stone really was, who owns Cullinan and Venetia now, and where De Beers stands after a hard 2026. Every number carries its source and date. Words such as carat (one carat is 0.2 grams), kimberlite (the volcanic rock that carries diamonds up from the mantle) and rough diamond (uncut stone) are explained where they first appear.

How Cecil Rhodes built De Beers

Rhodes was born on 5 July 1853 in Bishop’s Stortford, England, and went to Natal to work on his brother’s cotton farm, and later made his way into the Kimberley diamond fields (South African History Online, biography of Cecil John Rhodes). The ground he worked had been opened up in 1871, when the De Beers mine was found in May and the Kimberley mine in July. De Beers calls Kimberley the world’s richest mine for nearly a century.

The company name comes from the De Beer brothers, who owned the farm where the first pipes were found. They never ran the company that took their name (EARTH Magazine, American Geosciences Institute).

The steps from claim holder to near-monopoly

• 1871: diamonds are found at the De Beers and Kimberley sites. Thousands of small claim holders rush in.
• 1870s: Rhodes sees that changing rules in the diamond fields will push out small operators, and that only larger companies will survive. With his partner Charles Rudd he starts to consolidate claims (South African History Online).
• 12 March 1888: Rhodes and Barnato, who had been running competing operations, join forces. De Beers Consolidated Mines Limited is established, with Rhodes as chair (De Beers Group).
• 1902: Rhodes ends his chairmanship, and dies in the same year.
• 1926: Sir Ernest Oppenheimer joins the De Beers board after Anglo American, the company he founded, becomes a major shareholder.
• 2012: De Beers becomes a member of the Anglo American group (De Beers Group).

The aim behind the consolidation was simple. South African historians record that Rhodes wanted far more control over diamond production and distribution, to escape the repeated boom and bust of the trade. That control over supply, rather than any single discovery, is what gave De Beers its place in the diamond business for the next century.

What Rhodes left behind beyond diamonds

Rhodes also built a political career. He became Prime Minister of the Cape Colony in July 1890, and his British South Africa Company sent a Pioneer Column into Mashonaland that year. The territories the company took were named Southern and Northern Rhodesia, which are now Zimbabwe and Zambia (South African History Online).

Oxford historian William Beinart reviewed the evidence in a memorandum for Oriel College. He concludes that Rhodes advocated a racially restrictive franchise and other measures that intensified segregation in the Cape, that De Beers introduced closed compounds for African migrant workers in the mid-1880s, and that African deaths in the conquest of Zimbabwe in the 1890s were probably over 20,000 (Beinart, Oriel College, Oxford). These facts are why Rhodes remains a disputed figure: the company he built shaped how diamonds are mined and sold, and the empire he pursued took land and political rights from African people.

If you want the mining side of those countries today, our pages on gold exploration in Zimbabwe and gold exploration in Zambia describe the licences and geology in plain terms.

The Cullinan diamond: the 3,106-carat stone

The Cullinan is the largest gem-quality rough diamond ever found. It weighed 3,106.75 carats (621 grams) and measured about 10 by 6 by 6.5 centimetres. Mine manager Frederick Wells spotted it in the wall of the open pit on 26 January 1905, at the Premier mine east of Pretoria. Some accounts differ on the exact day and on the details of the find (EARTH Magazine).

The mine was started by Thomas Cullinan, a builder turned prospector, who bought the land in late 1902 after the Second Boer War. In its first year, the Premier mine produced 750,000 carats. The land and the company were separate from Rhodes’s De Beers. De Beers’ own history lists the Premier mine discovery in 1902 and says it would go on to produce more large gem diamonds than any other mine.

From mine to the Crown Jewels

• The Transvaal government bought the stone from the Premier company in 1907 and gave it to King Edward VII for his 66th birthday.
• The Asscher firm in Amsterdam split and cut it from February to September 1908, into nine major stones and 96 smaller ones. The polished stones weighed 1,055.9 carats in total, so nearly two thirds of the rough stone was cut away.
• The two largest, Cullinan I (530.2 carats) and Cullinan II (317.4 carats), went into the Sovereign’s Sceptre and the Imperial State Crown, which are on display at the Tower of London.

The stone’s record still stands. The 755.5-carat Golden Jubilee rough, found at the same mine in 1985, became the largest cut diamond in the world at 545.7 carats (EARTH Magazine).

Cullinan Mine today: who owns it and what it produces

Cullinan is no longer a De Beers mine. Petra Diamonds has operated it since 2008, and mines it underground by block caving, a method in which the rock is allowed to break and fall under its own weight. Petra calls the mine its flagship and says it could keep producing into the late 2040s (Petra Diamonds, Cullinan Mine page). Petra also describes the mine as the world’s most important source of rare blue diamonds, which is the company’s own claim.

Chart

Cullinan Mine average price per carat

US$ per carat, financial years ending 30 June

The figures below are from Petra’s published five-year table, with financial years ending 30 June. Carats produced fell from 1.94 million in FY 2021 to about 1.45 million in FY 2025. The average price per carat peaked at US$169 in FY 2022 and fell to US$96 in FY 2025. In FY 2026 it rose to US$106, even though the market was weak (Petra Diamonds, Q4 and FY 2026 operating update).

Petra explains the FY 2026 price rise by a shift to the C-Cut, the section that gives a larger share of big and fancy coloured stones, including a 41.82-carat blue diamond sold in the third quarter. The same update says that Petra started a Section 189A labour restructuring process in May 2026 that covers Cullinan and the wider company (a South African process for group job cuts), and that company guidance stays suspended. The update expected a new business plan in September 2026. Petra’s other South African mine, Finsch, entered Business Rescue in the fourth quarter.

Venetia Mine: South Africa’s largest diamond mine and the production pause

Venetia, in Limpopo province, opened in 1992 and became South Africa’s largest diamond mine (De Beers Group, company history). Open-pit mining ended in December 2022, and production from the US$2.3 billion underground operation began in July 2023. The mine produced 2.23 million carats in 2025, about 10.3% of De Beers’ rough output that year, and employs around 4,400 people (MINING.COM, 13 July 2026).

On 13 July 2026 De Beers announced that it intends to pause production at Venetia for two years while it rephases spending on the underground project. The company said it would keep investing in the infrastructure needed to ramp up again when the market recovers, and that overall production targets would not change because output shifts to other operations (MINING.COM; Mining Technology, July 2026). The pause is described as proposed and subject to regulatory requirements. De Beers expects most of this work to be done in the second half of 2026 (De Beers Group, interim results, 30 July 2026).

Until the pause, output was rising. Venetia recovered 1.47 million carats in the first half of 2026, 37% more than in the first half of 2025, because more underground ore went through the plant (De Beers Group, second quarter production report).

Land, water and wildlife around the mines

Two sourced examples are better than a list of general promises. In 2018 De Beers and the Peace Parks Foundation moved 200 elephants over 1,500 kilometres from the Venetia Limpopo Nature Reserve to the Zinave reserve in Mozambique, because the reserve was under capacity pressure (De Beers Group, company history). In 2020 De Beers launched its Building Forever sustainability strategy.

This guide does not quote water recycling rates, renewable energy shares or project counts for Cullinan and Venetia. For current figures, read the sustainability or integrated reports of De Beers (Venetia) and Petra Diamonds (Cullinan), which are published each year with audited scopes.

The video below explains the seven main environmental effects of mining in plain terms, which is useful context for any mine that uses open pits, tailings dams or large water supplies.

▶ A plain-language claymation on the seven environmental impacts of mining. · 2:31

Where African diamonds come from

Southern Africa still supplies a large share of the world’s gem-quality diamonds. The USGS estimates world gem-quality natural diamond production at about 69 million carats for 2025, with Russia the largest at 21 million. Angola, Botswana and Canada each made about 13 million. South Africa produced about 2.1 million carats, less than Botswana by a factor of six, and its reserves are estimated at 87 million carats (USGS, Mineral Commodity Summaries 2026, Gemstones).

Chart

Gem-quality natural diamond mine production, 2025 estimate

Million carats; seven of the largest producers in the USGS table

The chart shows seven of the largest producers in the USGS table. It is a rounded estimate for 2025 and it counts carats, not value, so it does not show how much a carat sells for. USGS counts gem-quality stones, while De Beers counts all rough recovered, so the USGS South Africa figure (2.1 million carats) cannot be compared with the 2.23 million carats De Beers reports for Venetia alone.

De Beers today: ownership, sale and prices

De Beers is still a member of the Anglo American group. Anglo American said in its 30 July 2026 interim statement that it is committed to selling De Beers and is running a formal sales process, with an update expected during 2026 (De Beers Group, interim results). Anglo first put the business up for sale in May 2024 (MINING.COM). Anglo American owns 85% of De Beers and the Government of Botswana owns the other 15% (Anglo American, diamonds). A Botswana government official said in July 2026 that Anglo had picked the Global Diamond Consortium, led by former De Beers chief executive Gareth Penny, as preferred bidder. Anglo has not confirmed this and says it is progressing the sale process (National Jeweler, 21 July 2026). No completed sale had been announced by 16 October 2026.

Chart

De Beers rough diamond production by country

Million carats recovered in the first half of each year (Canada on a 51% basis)

The group is in a downturn. For the first half of 2026 De Beers reported:

• rough diamond production of 14.9 million carats, 46% more than in the same period of 2025, mainly because the Orapa mine in Botswana was on extended maintenance in 2025;
• an average realised price of US$105 per carat, down 32% from US$155, with a 16% fall in the average rough price index;
• revenue of US$1.6 billion and an underlying EBITDA loss of US$113 million (EBITDA means earnings before interest, tax, depreciation and amortisation);
• 2026 production guidance unchanged at 21 to 26 million carats, with the Venetia pause and plant maintenance in Botswana reducing the second-half rate.

De Beers names lab-grown diamonds as one cause of pressure on prices of lower-value natural stones (De Beers Group, interim results). The chart shows how first-half production moved by country between the two years. Canada and Botswana rose sharply; Namibia fell slightly.

Diamond traceability and the Kimberley Process

Provenance is the other half of the De Beers story. The Kimberley Process Certification Scheme was set up in 2003 to stop the flow of conflict diamonds, and De Beers says all of its diamonds are certified under it as not linked to conflict. In 2017 the company invested in blockchain technology for a platform to track a diamond’s path through the value chain, and in 2023 Tracr and Sarine Technologies announced a joint effort on provenance for stones entering G7 countries (De Beers Group, company history).

A blockchain here means a shared digital record that cannot be edited by one party. It does not prove a stone’s origin by itself: the record is only as reliable as the data entered at the mine and at each hand-over, which is why buyers still ask for mine-level documents and independent audits.

What a diamond mine’s revenue looks like: a grade and price calculator

Diamond revenue is carats times price per carat. Carats come from the tonnes treated and the grade, which is quoted in carats per hundred tonnes (cpht). For scale, Petra reports a Cullinan run-of-mine grade of 29.7 cpht and an average price of US$96 per carat for FY 2025 (Petra Diamonds). The calculator below uses round example numbers, not Cullinan’s figures, so enter your own.

Watching mine sites from space

Large open pits, waste dumps and tailings dams are easy to see from orbit, and public satellite archives let anyone compare a site over several years. Farmonaut works with satellite imagery for mining licences, and this kind of before-and-after view is the simplest use: it shows how far a pit, dump or tailings area has grown, and where land is being rehabilitated. It does not measure diamond content, because diamonds are too small and too deep for satellites to detect directly. Analysts look instead for the kimberlite pipe’s surface expression, the shape of the land and the nearby geology.

The video explains in under three minutes what remote sensing for mining measures and what it cannot. For other African mining regions, see our page on gold exploration in South Africa.

▶ What remote sensing for mining measures, in about two minutes. · 2:01

We cover a connected topic in De Beers Lab-Grown Diamonds: Market Share, Prices, Sale.

Frequently asked questions

Who was Cecil Rhodes in the history of De Beers?

Rhodes was a British businessman and politician who consolidated Kimberley diamond claims. De Beers Consolidated Mines was established on 12 March 1888 and Rhodes served as its chair until 1902 (De Beers Group).

When was De Beers founded?

De Beers traces its history to 1888, when Cecil Rhodes and Barney Barnato joined their operations. The De Beers mine itself was found earlier, in May 1871.

Did Cecil Rhodes find the Cullinan diamond?

No. Rhodes died in March 1902. Thomas Cullinan bought the Premier mine land in late 1902, and the stone was found in January 1905.

How big was the Cullinan diamond?

It weighed 3,106.75 carats, or 621 grams, and is the largest gem-quality rough diamond ever found. It was cut into nine major stones and 96 smaller ones.

Where is the Cullinan diamond now?

The two largest stones, Cullinan I and II, are set in the Sovereign’s Sceptre and the Imperial State Crown at the Tower of London. The other seven major stones were gifted to the British royal family and set into brooches, necklaces and other pieces.

Who owns the Cullinan mine now?

Petra Diamonds has operated the mine since 2008. It is not a De Beers mine.

Who owns the Venetia mine?

Venetia is a De Beers mine in Limpopo, South Africa, and De Beers is part of Anglo American. Anglo has said it is working to sell De Beers, with an update promised during 2026. A preferred bidder was reported in July 2026, but no completed sale had been announced by 16 October 2026.

Is Venetia mine closing?

No closure has been announced. De Beers intends to pause production for two years while it rephases spending on the underground project. The pause is described as proposed and subject to regulatory requirements.

How many carats does De Beers produce a year?

De Beers guides for 21 to 26 million carats in 2026 on a 100% basis, and recovered 14.9 million carats in the first half of the year.

What is the Kimberley Process?

It is a certification scheme created in 2003 to stop conflict diamonds from entering the legal trade.