The company said the first stone is an exceptional quality 166 carat Type II white diamond, while the second one is a high-quality 77-carat yellow diamond.
Both diamonds were recovered on the same day, it said.
The 166-carat diamond is the 12th +100 carat diamond recovered at Letšeng so far this year.
Gem recovered a high-quality 233-carat Type II white diamond from Letšeng mine early this month.
It also unearthed a high-quality 442 carat Type II diamond last month.
Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished