Lucara Diamond Corp. will focus on the high-value section of its Karowe mine that produced the 1,109-carat Lesedi La Rona, after a survey indicated the area contained more large stones than previously predicted.
A sample of 13,562 carats from the south lobe’s EM/PK(S) unit yielded 47 diamonds weighing more than 10.8 carats, including one over 100 carats and six greater than 50 carats, Lucara said last week. The south section of Karowe is the most lucrative area the company is currently mining, with a forecast average selling price of $716 per carat.
By comparison, diamonds from the north lobe have an average value of $222 per carat, while Lucara estimates stones from the center lobe at $367 per carat.
EM/PK(S) is the most valuable part of the south lobe, containing diamonds with a potential average selling price of $753 per carat, based on the new sample. While the miner initially believed EM/PK(S) would provide 12% of the south lobe’s total carats, the new study increased that outlook to 51%.
“Going forward, the Karowe mine plan is dominated by south-lobe ore, with the high-grade, high-value EM/PK(S) unit becoming increasingly prevalent as we mine deeper,” Lucara CEO Eira Thomas said last week.