Lucara Diamond Corp. has unearthed a grapefruit-size, 2,492-carat diamond at its famous Karowe Mine in Botswana. The diamond ranks #2 on the list of the largest rough diamonds ever found. The 1,758-carat Sewelô, which was recovered from the same mine in 2019, is now in the third spot.

Of the top eight diamonds ever unearthed, the prolific Karowe Mine is credited with six of them. The still-unnamed discovery has a rugged silvery-white appearance and weighs in at 17.58 ounces (1.1 pounds). Maintaining the top spot is the 3,106-carat Cullinan, which was found at South Africa’s Premier Mine 2 in 1905.

Lucara's newest treasure remained unscathed during the recovery process thanks to the company’s state-of-the-art Mega Diamond Recovery ("MDR") X-ray Transmission ("XRT") technology, installed in 2017 to identify and preserve large, high-value diamonds. The stone was identified during the processing of EM/PK(S) kimberlite, the dominant ore type that Lucara has targeted during the first years of its underground mining operations.

Throughout history, diamond-bearing rock was typically drilled, blasted, hauled and put through crushing machines to expose the gems that may be hiding within. During that process, extremely large diamonds, some weighing hundreds of carats or more, were often damaged or even pulverized.

With the advent of XRT scanners, the mining process has become more delicate and discerning. As the rocky material comes down a conveyor belt, the scanners can pick out the diamonds based on their chemical composition. The diamond-rich material is then separated from the rubble and moved to a secure area for processing.

"We are ecstatic about the recovery of this extraordinary 2,492-carat diamond. This find not only showcases the remarkable potential of our Karowe Mine, but also upholds our strategic investment in cutting-edge XRT technology," said William Lamb, President and CEO of Lucara. "The ability to recover such a massive, high-quality stone intact demonstrates the effectiveness of our approach to diamond recovery and our commitment to maximizing value for our shareholders and stakeholders."

So, what will the future hold for a 2,492-carat rough diamond? It's likely to end up on the cutting wheel.

Nearly 120 years ago, the super-sized Cullinan was cut by the Asscher Company into nine principal diamonds and 96 smaller diamonds. The Cullinan I and II – known as the Great Star of Africa and the Lesser Star of Africa — are set in the Crown Jewels of Britain. They weigh 530 carats and 317 carats, respectively. The remaining seven principal diamonds, ranging in size from 94 carats to 4.39 carats, are in the collection of the British Royal Family.

Here's how the diamonds of the Karowe Mine rank on the list of the largest diamonds ever found.

2 - 2,492 carats, unnamed, 2024
3 - 1,758 carats, Sewelô, 2019
4 - 1,174 carats, unnamed, 2021
5 - 1,111 carats, Lesedi La Rona, 2015
7 - 1,080 carats, unnamed, 2023
8 - 998 carats, unnamed, 2020

Botswana's diamond industry delivers wide-ranging socio-economic benefits to the country that extend well beyond the mining sector. Its influence supports national development by funding critical areas such as education and healthcare.

Credits: Photos courtesy of CNW Group/Lucara Diamond Corp.