After fifth-biggest stone, miner finds another 149-carat diamond

By Thomas Biesheuvel

Fresh after finding the fifth-biggest diamond in history, miner Gem Diamonds Ltd. has discovered another giant stone in the mountainous kingdom of Lesotho in southern Africa.

Gem unearthed a 149-carat, D color type IIa diamond at its Letseng mine, the company said in a statement on Monday. Type IIa diamonds contain very little or no nitrogen atoms and are the most expensive stones.

It’s been an incredible start to the year for Gem. The company said last week it had found a 910-carat stone, about the size of two golf balls. Earlier in the month it discovered two type IIa diamonds that weighed 117 carats and 110 carats respectively.


910-carat diamond

The four discoveries this year will be a major boost to the company, which saw its value fall to a record low in December after struggling to find big stones in recent years and having to close a new mine in Botswana.

The Letseng mine is famous for the size and quality of the diamonds it produces and has the highest average selling price in the world. Gem sold a 357-carat stone for $19.3 million in 2015 and in 2006 found the 603-carat Lesotho Promise.