The larger of the two diamonds weighed 4.77 carats while second and smaller diamond weighed 0.2 carats.
Lucara is currently exploring various options to sell the recovered diamonds, having recently sold a 9.46 carat blue diamond recovered from the same mine for $4.515m.
Lucara CEO William Lamb noted that the 4.77 carat blue diamond is the fourth such diamond recovered in the past few months.
"The re-occurring recovery of these exceptionally rare and sought-after stones is highly significant and confirms the quality of the diamonds produced from the Karowe Mine," said Lamb.
The company also owns a 75% stake in the Mothae Project in Lesotho, where a trial mining program was recently completed.
