Booking choice: The surface walking tour, from $12 per person. Check dates Tour details
Some visitors arrive expecting a closed, historic mine. Cullinan is the opposite. It produced 1,398,604 carats in the year to June 2026 and is Petra Diamonds' flagship operation, mined by block caving more than 800 m below the village.
The confusion has two sources: the underground tours stopped in 2023, and in October 2026 Petra said it might sell assets. Neither means the mine has closed.
The quick answer
Yes. Cullinan is a working underground diamond mine, owned 74% by Petra Diamonds, 14% by Kago Diamonds and 12% by an employee trust. It produced 1,398,604 carats in the year to June 2026. In October 2026 Petra launched a strategic review that could include a sale, but nothing has been sold, and we found nothing to suggest the surface tours are affected.
Is the Cullinan Diamond Mine still operating in 2026?
Yes. Petra Diamonds runs it as an underground mine, and MiningMX called it Petra's flagship operating mine on 1 October 2026.
Petra's full-year update of 28 July 2026 lists Cullinan's output, revenue and plans to open more production areas in the C-Cut, and calls it a world-class asset. It is now Petra's only remaining mine: Rapaport reports that Koffiefontein was sold in 2024 and Williamson in Tanzania in 2025, and Finsch went into business rescue in 2026.
It has not been an easy year. Petra opened a Section 189A process in May 2026, the South African legal procedure for large-scale job cuts, and suspended its guidance while it rewrote the business plan.
Who owns the Cullinan Diamond Mine?
Petra Diamonds owns 74%, Kago Diamonds 14% and the Itumeleng Petra Employee Trust 12%. De Beers owned it until 2008.
Ownership over 120 years, from Petra, SAIMM and Mining Technology:
| Year | What happened |
|---|---|
| 1902 | Registered as the Premier Mine; Thomas Cullinan is owner and chairman |
| 1917 | De Beers takes a controlling interest |
| 2003 | Renamed Cullinan Diamond Mine for its centenary |
| 2007 | De Beers agrees to sell for R1 billion to a Petra-led consortium |
| 2008 | Deal completed on 16 July; Petra holds 37% |
| 2009 | Petra raises its stake to 74% |
| 2026 | Petra launches a strategic review; no sale agreed |
Tours are not run by Petra. Visits go through independent operators based on Oak Avenue in the village, which is why the mine's own website has no booking page.
The working mine, from the shafts to the Big Hole lookout, with a guide: from $12.
Check dates for the surface walking tourIs Cullinan for sale? What the October 2026 strategic review means
Not sold. On 1 October 2026 Petra started a strategic review with its lenders that may include selling assets, and said the outcome is uncertain.
The facts so far: Petra announced the review together with its lien creditors and said it could include a possible sales process for its assets, with no certainty about the outcome (MiningMX). Net debt was US$322 million at the end of June 2026. On 5 October Mining Weekly reported that Petra had appointed Questco Corporate Advisory to run it. Its July update had already warned that if refinancing terms were not agreed by the end of October, the senior lender could start a sales process.
For visitors, nothing changes for now. Our strategic review post follows the story as it moves.
How deep is the Cullinan mine?
Production comes from about 839 m below surface, No. 1 Shaft hoists from 934 m, and the deepest planned resource is at 1,073 m. The open pit, the Big Hole, is about 190 m deep.
The figures come from a 2016 paper in the SAIMM journal:
| Level | Depth below surface |
|---|---|
| Big Hole (old open pit) | About 189 to 190 m |
| Gabbro sill cutting the pipe | About 350 to 525 m |
| Older block caves | 630 to 747 m |
| C-Cut production level | 839 m level |
| No. 1 Shaft hoisting | From 934 m |
| Lowest C-Cut resource | 1,073 m |
The pipe itself is carrot-shaped: about 860 by 400 m at surface, covering 32 ha, narrowing to 12 ha at 1,000 m. Subsidence has pulled the rim out to more than 40 ha, which is why the Big Hole looks so wide from the lookout.
How does Cullinan mine diamonds today?
By block caving and sub-level caving underground, with extra carats from retreating old tailings.
In a block cave, miners undercut a huge block of kimberlite so it breaks up under its own weight, then draw the broken ore from below. Petra says current production comes from the C-Cut, with the CC1-East and C-Cut extension projects approved, and that mining could continue into the late 2040s (Petra).
The timeline: open-pit mining from 1903, closure in 1932 during the Depression, dewatering from 1945, underground mining from 1946 or 1947 (GIA and SAIMM differ), and caving from the early 1970s. In the year to June 2026, 224,171 of the mine's carats came from reprocessed tailings rather than fresh ore (Petra).
Stand beside the shafts that hoist this ore, then look into the pit where it all started.
Explore the surface walking tour Tour detailsHow many diamonds does Cullinan produce?
About 1.4 million carats a year: 1,398,604 carats in the year to June 2026, sold for US$149 million at an average of US$106 a carat.
Petra's own figures (Petra, FY2026 update):
| Year to June | Carats produced |
|---|---|
| 2022 | 1,814,975 |
| 2023 | 1,485,846 |
| 2024 | 1,404,791 |
| 2025 | 1,453,008 |
| 2026 | 1,398,604 |
Over its life the mine has yielded nearly 120 million carats from more than 350 million tonnes of ore, plus about 20 million from tailings (Mining Technology). It has produced more than 750 stones over 100 carats. You may also read that it produces 25% of the world's gem diamonds: we found no source behind that claim.
Why is Cullinan famous for blue diamonds?
Petra calls it the world's most important source of blue Type IIb diamonds, and it keeps finding big ones: 39.34 carats in 2021, 41.82 carats in December 2025.
Type IIb diamonds owe their blue to traces of boron and are among the rarest of all. The 39.34-carat stone sold in 2021 for US$40.18 million (Petra). The 41.82-carat blue was announced on 13 January 2026 and sold by tender at a confidential price, under a profit-share deal, to be cut and polished in South Africa (Mining Weekly).
The whole roll of honour is in the famous diamonds guide, and the blue diamond post covers the latest find.
A small-group surface tour with a history room and a heritage house: the Royal Africa tour.
Check dates for the Royal Africa tourCan you visit a working diamond mine at Cullinan?
Yes, on a surface tour run by independent operators in the village. Underground visits stopped in April 2023.
Two operators run tours from Oak Avenue: Premier Diamond Tours, which lists daily walking tours at 10:30 and 12:00 for R200, and Fundani. Send the visitor form with ID copies two working days ahead and wear closed flat shoes. The underground tour guide explains what the surface tour includes.
No car needed: a private guide, hotel pickup, Pretoria in the morning and the working mine in the afternoon.
Explore the Pretoria and Cullinan day Tour detailsFrequently asked questions
Did De Beers sell the Cullinan mine?
Yes. De Beers agreed in November 2007 to sell it for R1 billion to a Petra-led consortium, and the deal completed in July 2008.
Is Cullinan the biggest diamond mine in the world?
No. Its output of about 1.4 million carats a year is modest. Its fame rests on very large stones and blue diamonds. Jwaneng in Botswana is described as the richest diamond mine by value.
How long will the Cullinan mine operate?
Petra says mining could continue into the late 2040s, based on the C-Cut extensions and the CC1-East project.
Does the strategic review affect tours?
Not that we can find. The review concerns Petra's finances and ownership; the surface tours are run by independent operators in the village.
Ready to book
Choose your tour
Free cancellation up to 24 hours before on every option. Prices are from-prices in USD and move with the season.
Cullinan Surface Diamond Mine Walking Tour
- Guided surface walking tour, about 2 hours
- The Big Hole lookout and the shaft area
- Diamond display with replicas of famous stones
Royal Africa Diamond Mine Tour
A small-group surface tour with a history room and a heritage house
Pretoria City Tour and Cullinan Diamond Mine
- Private group with your own guide
- Hotel pickup and drop-off
- Pretoria city stops in the morning
