De Beers pauses South Africa's largest diamond mine as lab-grown gems reset the market

Overview

Updated Sep 7

De Beers is pausing production at Venetia, South Africa's largest diamond mine, for two years. The mine accounts for 40% of the country's diamond output and employs about 4,400 people, but every carat it sold last year fetched $66 while extraction cost $110.

The shutdown is one of several closures rippling through South Africa's diamond belt. Petra Diamonds is restructuring its Finsch and Cullinan mines, putting about 1,800 more jobs at risk. Lab-grown stones took more than 45% of American engagement-ring purchases and cost roughly 80% less than natural ones, so De Beers' parent Anglo American has cut the company's carrying value from $12.75 billion to $2.3 billion and is now selling it to a consortium led by former De Beers chief Gareth Penny.

Why it matters

Lab-grown diamonds reset the price of natural stones, forcing South Africa's biggest mine to close and threatening thousands of jobs in communities with few alternatives.

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Key Indicators

$2.3B

De Beers carrying value

Down from $12.75 billion in 2011; Anglo American has written down the brand three times in 3.5 years.

$105

Average rough diamond price per carat, H1 2026

Anglo American reported a 32% decline from the same period a year earlier.

45%

Lab-grown share of US engagement-ring purchases

Up from near zero a decade earlier; lab-grown retail prices fell 74% between 2020 and 2024.

4,400

Workers at Venetia mine

1,134 permanent employees plus 80 Johannesburg sorting-facility staff face retrenchment; most live in municipalities with few other employers.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Gareth Penny

Former De Beers managing director; leads consortium bidding for the company

Preferred bidder to acquire De Beers from Anglo American

Jackie Mapiloko

De Beers spokesperson

Confirmed section 189 retrenchment consultations had begun

Willie Venter

Deputy secretary general, Solidarity trade union

Warned of job losses in areas with few alternatives

Nico van Rooyen

Divisional manager for minerals sector, United Association of South Africa (Uasa)

Argues the diamond industry still has a future

Organizations Involved

De Beers

Diamond mining company

Pausing production at Venetia for two years; being sold by Anglo American

Diamond mining company, majority-owned by Anglo American, that once controlled about 90% of world rough supply.

Anglo American

Mining conglomerate

Selling De Beers; has written down its value three times

London-based mining giant and majority owner of De Beers.

Petra Diamonds

Diamond mining company

Restructuring Finsch and Cullinan mines

Operator of South Africa's Finsch and Cullinan diamond mines, both now facing closure or restructuring.

National Union of Mineworkers (NUM)

Trade union

Flagged 1,200+ employees affected by Venetia shutdown

South Africa's largest mining union, representing workers at De Beers and Petra Diamonds.

Timeline

May 2024 September 2026

7 events Latest: September 5th, 2026 · 2 months ago

Tap a bar to jump to that date

September 2026
WSJ reports diamond mine closures leave South Africans with few alternatives
Latest Media Coverage

Weak sales and lab-grown stones endanger livelihoods of thousands of De Beers mine workers.
September 5th, 2026
July 2026
Union reveals 1,200+ jobs at risk across diamond sector
Labor

NUM flags 1,134 Venetia staff and 80 sorting-facility workers; Petra's Finsch and Cullinan put 1,779 more jobs on the line.
July 25th, 2026
Retrenchment consultations begin at De Beers
Labor

Section 189 consultations start; job numbers not yet determined.
July 14th, 2026
De Beers announces two-year production pause at Venetia
Corporate Announcement

Cites weak trading conditions and high costs; plans continued investment in underground infrastructure during the pause.
July 13th, 2026
Botswana confirms preferred bidder for De Beers
Merger/Acquisition

Consortium led by former De Beers MD Gareth Penny selected as Anglo's preferred buyer.
July 2026
February 2026
Anglo American writes De Beers down to $2.3 billion
Financial

Third impairment in 3.5 years; carrying value falls 82% from the 2011 peak of $12.75 billion.
February 2026
May 2024
Anglo American announces intent to exit De Beers
Corporate Strategy

Anglo American publicly declared it would sell its majority stake in the diamond company.
May 2024

Scenarios

De Beers sale to Penny consortium closes; Venetia restarts in 2028

Possible Resolves by Q1 2027

Discussed by: Business Day, AMIQ Insights

The Gareth Penny consortium completes its acquisition of De Beers, keeps the two-year production pause at Venetia, and uses the downtime to finish critical underground infrastructure. The mine restarts in 2028 as planned if rough prices recover to a level that clears its costs. The underground expansion is designed for 4 to 4.5 million carats a year into the 2040s.

Venetia never reopens; mine enters permanent care and maintenance

Unlikely Resolves by Jul 13, 2028

Discussed by: AMIQ Insights; analysts quoted in Business Day

If rough prices stay below the mine's cost curve past the pause, new owners decide the economics of the $2.3 billion underground expansion don't justify reopening. The skills that walk away in retrenchment are the hardest to bring back, and communities around Musina and Blouberg lose their main employer permanently.

Anglo American fails to sell De Beers; further writedowns follow

Unlikely Resolves by Q2 2027

Discussed by: Business Day; Anglo American restructuring coverage

If the Penny consortium deal falls through, Anglo American is left holding a business it has impaired three times. The failed sale complicates the planned merger with Teck Resources and likely forces another writedown, making De Beers cheaper for a future buyer or leading to a break-up of its parts.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

1930s

De Beers stockpiles during the Great Depression (1930s)

With diamond demand collapsed, De Beers chairman Ernest Oppenheimer halted sales and stockpiled rough stones rather than cut prices. The company controlled about 90% of world supply, so it could set the terms.

Then

Diamond prices held through the Depression, and the stockpile sold profitably after World War II.

Now

The episode cemented De Beers as the global price-setter for rough diamonds for five decades.

Why this matters now

De Beers today controls roughly a third of supply, and lab-grown producers are outside any cartel. The lever that protected prices in the 1930s no longer exists.

November 2020

Rio Tinto closes Australia's Argyle mine (2020)

After 37 years, Rio Tinto shut Argyle in Western Australia, the world's largest source of pink diamonds. The mine was depleted, not unprofitable, and its closure removed a major supply source from the market.

Then

Argyle pink diamonds became scarce, and their auction prices rose sharply after closure.

Now

Proved that removing a major supply source can support prices — the opposite of what De Beers faces, where demand has shifted to an unlimited lab-grown alternative.

Why this matters now

When a diamond mine closes, the market can absorb the loss. The difference here is that demand isn't returning to natural stones — it has moved to synthetic ones.