The Karowe mine, in Botswana, has produced the world’s second-largest uncut diamond, Canadian company Lucara Diamond Corp announced on Thursday, sending the miner’s share price up 11% to C$1.68 a share.
At 1 758 ct, the diamond is second in size only to the 3 106 ct diamond that was mined at Cullinan, South Africa, in the early 1900s.
The latest Karowe find is now the largest diamond recovered in Botswana and dethroned the Lesedi La Rona, which previously held the titles as the country’s largest and the world’s second largest.
The 1 109 ct Lesedi La Rona was recovered in November 2015, and was sold only two years later at $53-million.
Although impressive in size, the new Karowe whopper, which weighs close to 352 g and measures 83 mm by 62 mm by 46 mm, is not gem quality and has been characterised as “near gem of variable quality, including domains of high-quality white gem”, Lucara said in a statement.
"Lucara's technologically advanced, XRT diamond recovery circuit has once again delivered historic results. Karowe 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, 1 000 ct diamonds,” said CEO Eira Thomas.
Since commissioning of the XRT circuit in 2015, a total of 12 diamonds of more than 300 ct have been recovered at Karowe, including the two 1 000-ct-plus stones, from a total production of about 1.4-million carats. Of the 12 diamonds that were larger than 300 ct, half were categorised as gem quality with 11 sold to date generating revenue of $158-million.