In 2021, Gem Diamonds found only six diamonds over 100 carats at Letšeng. This compares to 16 rocks of more than 100 carats discovered in 2020.
The find comes as prices for small diamonds have jumped about 20% since the start of March, as cutters, polishers and traders struggle to source stones outside Russia.
State-owned Alrosa (MCX: ALRS), the world’s top diamond producer by output, was hit with US sanctions following Moscow’s invasion of Ukraine.
Since acquiring Letšeng in 2006, Gem Diamonds has found more than 60 white gem quality diamonds over 100 carats each.