Lucara Diamond Corp. has unearthed six diamonds over 100 carats from its Karowe mine in Botswana, including a light-brown stone weighing 470 carats.
The miner recovered the clivage diamond — one of lower quality, which needs to be cut before processing — from the site’s south lobe EM/PK(S) area, known for its large, high-quality rough, it said Tuesday. The stone is Lucara’s third over 300 carats this year. In January, it found two high-quality diamonds weighing 341 and 378 carats.
The miner discovered the stone during a recent production run that included five additional 100-carat-plus diamonds of both gem and clivage quality. Along with those stones, weighing 265, 183, 161, 116 and 106 carats, were 13 diamonds between 50 and 100 carats.
Special-sized stones — those over 10.8 carats — accounted for 13% of the total carat weight of May’s output, exceeding Lucara’s resource expectations for Karowe, it explained.
Including the current batch, Karowe has produced 10 diamonds over 100 carats this year.
“The benefits of a south lobe-dominated mine plan continue to be realized in 2021, and [this] underpins our confidence in the ever-improving Karowe resource as we mine deeper in the open pit to 2026 and move into underground mining out to at least 2040,” said Lucara CEO Eira Thomas. “Both main rock types from the south lobe continue to deliver large, high-value diamonds, including six diamonds greater than 200 carats in the first five months of this year alone.”