Gaborone: Lucara Diamond Corp. broke a world record for the sale of a rough diamond as an 812.77-carat stone from its Karowe mine in Botswana fetched $63.1 million.

Dubai-based Nemesis International DMCC paid $77,649 per carat for the rights to 90 percent of stone, named ‘The Constellation.’ Lucara will retain a 10-percent interest in the net profit received from the sale of the resultant polished diamonds, the company said.

Lucara discovered the diamond in November alongside a 1,109-carat gem later labelled the Lesedi La Rona.

The sale comes ahead of the much-anticipated auction of the Lesedi La Rona at Sotheby’s London on June 29, which is expected to fetch upwards of $70 million.

“The sale of the 813-carat diamond is the highest price ever achieved for a rough diamond, breaking all records,” said William Lamb, Lucara’s president and chief executive officer. “We look forward to the next stage of Lucara’s development with the sale of the spectacular 1,109 carat, Lesedi La Rona diamond.”