Canadian miner Lucara Diamond Corp has recovered a 1 758 ct uncut diamond – the world’s second-largest – from its wholly owned Karowe diamond mine, in Botswana.
The unbroken stone, one of the largest diamonds in recorded history, the largest diamond recovered in Botswana, and the largest diamond to be mined at Karowe to date, was recovered through Lucara’s state-of-the-art X-ray transmission (XRT) circuit, commissioned in April 2015.
Weighing close to 352 g and measuring 83 mm × 62 mm × 46 mm, the diamond has been characterised as near gem of variable quality, including domains of high-quality white gem. Further detailed analysis is ongoing.
Since commissioning the XRT circuit in 2015, a total of 12 diamonds of more than 300 ct have been recovered at Karowe, including two greater than 1 000 ct, from a total production of about 1.4-million carats. Of these 12 diamonds recovered, 50% were categorised as gem quality, with 11 sold to date generating revenue of more than $158-million.
“Lucara’s technologically advanced, XRT diamond recovery circuit has once again delivered historic results,” says Lucara Diamond Corp CEO Eira Thomas.
The 1 109 ct Lesedi La Rona diamond was discovered in November 2015 and consolidated Lucara’s flagship Karowe mine as a regular producer of desirable exceptionally rare and large diamonds, Mining Weekly reported in 2017.
“The Karowe diamond mine has now produced two diamonds greater than 1 000 ct in just four years, affirming the coarse nature of the resource and the likelihood of recovering additional, large, high-quality diamonds in the future, particularly as we mine deeper in the orebody and gain access to the geologically favourable EM/PK(S) unit, the source of both of our record-breaking, plus-1 000-ct diamonds,” she concludes.