The 2,492-carat diamond was found in the Karowe diamond mine and was detected by the company’s X-ray transmission technology.
It is the latest recovery from the Karowe mine following the discovery of a 1,758-carat diamond in 2019 and a 1,109-carat diamond in 2015.
It is the biggest find since the 3,106-carat Cullinan diamond, found in South Africa in 1905.
Botswana is the world’s largest diamond producer by value, the IMF has said. Diamonds account for around 80pc of exports from the country.
A number of exploration companies are active in the region, including John Teeling’s Botswana Diamonds.
“We set up a company in 2002 called African Diamonds and we joint-ventured with (diamond company) De Beers at that time,” Mr Teeling, who is chair of Botswana Diamonds, said.
“In 2004, we hit what is now the Karowe mine.
“It took seven years, that came on stream at the end of 2011 and was acquired by (Lucara parent company) Lundin Group, who still own it.”
The company, which became known as Botswana Diamonds after the sale of Karowe, kept the exploration interests of African Diamonds and has been searching for diamonds since 2011. It also has a small operation in South Africa.
“Botswana is the home of big diamonds,” Mr Teeling said.
“We’re continuing to explore there. Botswana is 93pc sand so it can be expensive and difficult.
“The chances of finding another Lucara (diamond) are about one in 2,500. There have probably been about 50 hard rock diamond mines ever discovered in the world,” he said.
Botswana Diamonds, which has the second-largest diamond exploration database in the country, has introduced an artificial intelligence programme in recent weeks to support its search for diamond deposits.
Currently, the business has a database of around 375,000 square kilometres of geological data, Mr Teeling said.
The mineral prospectivity technology, which has been created by UK group Planetary AI Ltd, is set to analyse the existing data that has been collected by Botswana Diamonds.
Initial results are expected in six to eight weeks.
