The diamond has been shown to Botswana's President Mokgweetsi Masisi, who thus became one of the first to see it.
With a weight of 2,492 carats, the diamond is the second-largest rough diamond ever found. It is not far behind the world's largest diamond, the Cullinan diamond, which weighed 3,106 carats uncut and was found in South Africa in 1905. It was later divided into eleven parts, most of which are set in the British crown jewels.
Found with X-ray
One carat is 0.2 grams, which means that the newly discovered diamond weighs almost half a kilo. It was found in the Karowe mine using X-ray equipment installed specifically to detect valuable gemstones.
The listed company Lucara, with the Swedish Lundin family as one of the main owners, has not yet disclosed a value but says it is a diamond of high quality.
Two other major diamond finds have previously been made in the mine. One of them, the Sewolo diamond, weighing 1,758 carats, was found in 2019 and was then the world's second-largest diamond. It was later bought by Louis Vuitton for an unknown sum. The other, Lesedi La Rona, found in 2015, weighed 1,109 carats. It was sold in 2021 for $53 million.
Major diamond producer
For comparison, the famous Indian diamond Koh-i-noor is only 108.93 carats.
Botswana is one of the world's largest diamond producers, and production accounts for around 30 percent of the country's GDP.
On the Stockholm Stock Exchange, Lucara's share price is surging by over 80 percent.
Corrected: An earlier version incorrectly stated the weight of the diamond.