The full story
The Big Hole, from first find to museum
The Kimberley Mine, better known as the Big Hole, is one of the most famous mines ever dug. It began as a low hill, Colesberg Kopje, on a farm in what was then Griqualand West. Diamonds were found there in July 1871, a few years after the first South African diamond, the Eureka, turned up near Hopetown in 1867.
The rush
The discovery set off the "New Rush". The hill was divided into small square claims, each worked by its owner and hired labourers, and the diggings became the town of Kimberley. Up to 50,000 people dug the hole by hand with picks and shovels. Because each claim went down at its own pace, the mine soon looked like a field of pillars at different depths, linked to the rim by hundreds of aerial ropeways.
Why the claims had to merge
Deep, narrow claims were dangerous and expensive. Walls collapsed onto neighbours, water flooded the workings and pumping had to be shared. Through the 1870s and 1880s claims were bought up into companies, and in March 1888 De Beers Consolidated Mines was formed. In July 1889 a cheque for £5,338,650 was paid for the assets of Kimberley Central, the last large rival in the mine, ending a long contest between Cecil Rhodes and Barney Barnato.
The pipe and the closure
The diamonds come from kimberlite, named after the town: the rock that fills the pipe-shaped necks of ancient volcanoes. Near the surface it is weathered to soft "yellow ground"; deeper it is hard "blue ground". The open pit reached about 240 m before mining moved underground, following the narrowing pipe to 1,097 m. The mine closed on 14 August 1914, having yielded about 2,722 kg (13.6 million carats) of diamonds from more than 22 million tonnes of rock.
What it looks like today
The pit is about 463 m across and covers 17 hectares. It was partly filled with debris to about 215 m and has since taken on about 40 m of water. It is often called the largest hand-dug hole in the world, a claim disputed by the Jagersfontein mine.
Why it still matters to the mining business
- Fragmented ownership of one orebody does not last: shared walls, water and haulage pushed Kimberley to consolidation, the same logic behind joint ventures over shared pits today.
- Controlling supply set the price of diamonds for a century. Laboratory-grown stones now challenge that model, and the value of rough output fell in 2024.
- Closure is forever: the Big Hole is still a public site more than a century on, which is why closure plans and water management sit in every modern permit.
Questions people ask
How deep is the Big Hole in Kimberley?
The open pit was dug to about 240 m. It was later partly filled with debris to about 215 m, and water now fills the bottom 40 m or so, leaving about 175 m visible. Underground shafts below the pit reached 1,097 m.
How many diamonds came out of the Big Hole?
About 2,722 kg, or roughly 13.6 million carats, from more than 22 million tonnes of rock, before the mine closed in 1914.
Is the Big Hole the largest hand-dug hole in the world?
It is often called that, but the claim is disputed: the Jagersfontein mine, also in South Africa, has a competing claim.
Who owned the Kimberley mine?
At first it was split into many small claims worked by individual diggers. Over the 1870s and 1880s the claims were bought up into companies, and in 1888 to 1889 they were consolidated under De Beers Consolidated Mines, which bought out Kimberley Central for £5,338,650.
