Gem Diamonds big discoveries reach a dozen

Africa-focused Gem Diamonds (LON:GEMD) must be getting used to recovering huge precious rocks from its flagship Let??eng mine in Lesotho, as it has just dug up another massive one.

The 138-carat, top white colour Type IIa diamond is 12th diamond over 100 carats the company finds this year, beating the 11 it dug up in 2015.

The largest diamond found this year is a 910-carat D colour type IIa diamond, about the size of two golf balls, which was named the "Lesotho Legend." It became the second largest recovered in the past century and sold for $40 million at an auction in March.

Since acquiring Let??eng in 2006, Gem Diamonds has found now five of the 20 largest white gem quality diamonds ever recovered, which makes the mine the world's highest dollar per carat kimberlite diamond operation.

At an average elevation of 3,100 metres (10,000 feet) above sea level, Let??eng is also one of the world's highest diamond mines.

The biggest diamond ever found was the 3,106-carat Cullinan, dug near Pretoria, South Africa, in 1905. It was later cut into several stones, including the First Star of Africa and the Second Star of Africa, which are part of Britain's Crown Jewels held in the Tower of London.

Lucara's 1,109-carat Lesedi La Rona was the second-biggest in record, while the 995-carat Excelsior and 969-carat Star of Sierra Leone were the third- and fourth-largest.