Second-largest diamond ever found unveiled in Botswana

The largest uncut rough diamond seen in more than a century has been discovered in Botswana and is claimed to be surpassed only by one that forms part of the Crown Jewels.
The massive 2,492-carat gem, the size of a human palm, could be worth about $40 million and was discovered by a Canadian mining company in the Karowe diamond mine in northeast Botswana.
It was “one of the largest rough diamonds ever unearthed” and was detected using x-ray technology installed in 2017 to identify and preserve large, high-value gems, the Lucara Diamond Corporation said.
“I’m told this is the largest diamond to be discovered in Botswana to date and the second in the world,” President Masisi of Botswana said after being shown the gem. He congratulated the company on the find, adding: “This is precious.”
William Lamb, the president and chief executive of Lucara, said: “We are ecstatic about the recovery of this extraordinary 2,492-carat diamond.”
The largest diamond ever found was the 3,167-carat black Sergio stone, which was discovered above ground in Brazil in 1895 but was cut up to be used in industrial drills. Black “carbonado” stones such as the Sergio are thought to be parts of meteorites.
Large gemstones are valued for colour, clarity, cut and carat (weight). In terms of potential jewellery, the newly discovered clear rough diamond is said to be second only to the 3,016-carat Cullinan Diamond, which was discovered in South Africa in 1905.
That stone, named after Sir Thomas Cullinan, the chairman of the mining company that unearthed it, was cut into nine large stones and 100 smaller polished gems that are part of the Crown Jewels. They include the Cullinan I or Great Star of Africa which was set in the Sovereign’s Sceptre for the coronation of George V in 1910, and the Cullinan II, the cushion-shaped diamond that adorns the front of the Imperial State Crown. Other cut diamonds from the Cullinan are part of the royal family’s personal collection.
Lucara found a 1,174-carat diamond stone in Botswana in 2021 using the same x-ray technology. Before that the company’s biggest find was a 1,758-carat stone found in the Karowe mine in 2019 and named Sewelo.
The arid, land-locked country of Botswana is one of the world’s largest producers of diamonds, which are its main source of income, accounting for 25 per cent of GDP and 80 per cent of its exports, according to International Monetary Fund figures.
The Karowe mine started production in 2012 and has since then sold 216 diamonds for more than $1 million (£764,000) each and more than 11 single diamonds for more than $10 million each, Lucara said.
The company pays to the Botswana government a royalty of 10 per cent of the gross sales value of diamonds produced from Karowe, regardless of whether the diamond is sold rough or polished.
“With a diamond of this magnitude, I can see roads being built,” Masisi said, as he posed for pictures with the huge stone.
Tobias Kormind, managing director of Europe’s largest online diamond jeweller, 77 Diamonds, confirmed it was the largest rough diamond to be unearthed since the Cullinan.
“This discovery is largely thanks to newer technology that allows larger diamonds to be extracted from the ground without breaking into pieces. So we will likely see more where this came from,” he said.
The most expensive diamond ever sold at auction was the Pink Star, sold in 2017 for $71.2 million.
Lucara did not provide an estimation of the value of its latest find. The Financial Times reported that unnamed sources close to the company estimated the stone could be worth upwards of $40 million. Potential buyers included jewellery houses such as Louis Vuitton, Tiffany, Chopard or Bulgari, it added.
The diamond mining industry has recently been hurt by a growth in purchases of lab-grown gems and weaker spending, but Lucara’s share price jumped by about 40 per cent on Thursday after it announced the find.
“Diamond prices are going through a difficult time now,” Masisi said. “But every diamond is precious and valuable. We have to optimise and get the best price for this diamond.”