The Jewelers Bench
June 17th, 2021
And the gigantic diamonds just keep coming… Lucara just released details about a 470-carat top light brown diamond — the latest high-profile discovery from its prolific Karowe Mine in Botswana. The diamond ranks #36 on the list of the largest rough diamonds of all time.



During the past six years, the Karowe Mine has made an indelible mark on the precious stone sector by producing seven of the world's top 36 diamonds, including the #2-ranked 1,758-carat Sewelô (2019), the #3-ranked 1,109-carat Lesedi La Rona (2015), the #4-ranked 998-carat unnamed diamond (2020) and the #9-ranked 812-carat Constellation (2015).

Year to date, Karowe has produced 10 diamonds greater than 100 carats, including the 341-carat and 378-carat top white diamonds recovered back-to-back in January of this year.

Lucara's latest find, which measures 49mm x 42mm x 26mm (about the size of a golf ball) and displays a light-brown tint, was recovered in the the company's Coarse XRT circuit, a system that uses advanced technology to identify 100-carat-plus diamonds. By monitoring the rocky material for X-ray luminescence, atomic density and transparency, the new technology can identify and isolate large diamonds before they go through the destructive crushing process.

Despite its massive size, Lucara’s newest find tips the scales at barely 15% of the weight of the granddaddy of them all — the 3,106-carat Cullinan Diamond, which was discovered in South Africa in 1905. Polished gems cut from the Cullinan Diamond include the Cullinan I (530.20 carats) and the Cullinan II (317.4 carats).

Lucara reported that its May 2021 production run produced an unexpectedly high percentage of diamonds greater than 10.8 carats. These larger rough gems accounted for 12.7% of the mine's output, by weight.

The Karowe Mine is expected to be turning out high-value rough gems until 2046 under a renewed licensing agreement between Lucara Diamond Corp. and the Government of Botswana. Signed in January, the 25-year deal between Lucara Diamond Corp. and the Government of Botswana will pave the way for the underground expansion of Karowe, which has been operating since 2012.

Credit: Image courtesy of Lucara Diamond Corp.