Since the start of the second quarter, Karowe deposit produced 239 diamonds larger than 10.8 carats, including 27 diamonds with weights between 50 and 100 carats, the company said.

Of the thirteen-recovered stones, eight are classified as gem quality diamonds with five of them weighing 259 carats, 239 carats, two stones weighing 153 carats each and a 133 carats stone.

Lucara Diamond president and CEO William Lamb said: "The ongoing recovery of such stones is encouraging for a potential third exceptional stone tender during the fourth quarter of 2014."

Meanwhile, Lucara is preparing to conduct its second Exceptional Stone Tender on 18 July 2014 will client viewings in both Antwerp and Gaborone.