The Karowe mine in Botswana — one of the world’s most prolific producers of large and high-value type IIA diamonds — is the only diamond mine in recorded history to have produced two stones greater than 1,000 carats.
Lucara said the unbroken 549 carat white diamond is the fourth-largest diamond found at Karowe and the first large gem it has recovered from its Mega Diamond Recovery XRT circuit. The MDR circuit allows for diamond recovery after primary crushing and prior to milling and was commissioned in 2017.
The diamond was recovered from direct milling of ore sourced from the EM/PK(S) unit of the mine’s South Lobe and follows the recent recovery of another gem quality 176 carat stone from the same ore block.
Edward Sterck, a mining analyst with BMO Capital Markets in London, estimated the 549 carat diamond could fetch more than US$15 million.