Image: Gem Diamonds

Gem Diamonds has unearthed a 357-carat diamond at its Letšeng mine in Lesotho, it said in a Twitter post Monday.

The light-brown stone, which the miner said is of “high quality,” is the 13th rough diamond over 100 carats the company has found this year. It’s the second-largest it has recovered in 2018, after the 910-carat Lesotho Legend it found in January.

That stone — which the company claims to be the fifth-largest gem-quality rough diamond in history — sold for $40 million in March.

Gem Diamonds owns 70% of the Letšeng asset, with the government of Lesotho holding the remaining 30%.

Gem Diamonds at a glance

The Group owns the Letšeng Diamond mine in Lesotho and the Ghaghoo mine in Botswana, with Head Offices in the United Kingdom and Sales Marketing and Manufacturing capabilities in Belgium.

Letšeng is renowned for its regular production of large, top colour, exceptional white diamonds, making it the highest average dollar per carat kimberlite diamond mine in the world.

Since Gem Diamonds acquired Letšeng in 2006, it has produced over 60 +100 carat, large, top colour, exceptional white diamonds.

In addition, Letšeng has produced high quality pink and blue diamonds, with a rare blue diamond achieving a sales price of US$ 603.047 per carat in 2013 and an exceptional pink diamond achieving US$ 187.700 per carat in 2016.