Gem Diamonds found this high-quality 80-carat rock in Lesotho

The 80-carat, D-colour Type-II diamond is one of the highest-quality stones to come out of the company’s Letšeng mine. (Image courtesy of Gem Diamonds)

Shares in Gem Diamonds (LON:GEMD) spiked Thursday after the miner announced it had unearthed one of the highest-quality stones to come out of its Letšeng mine in Lesotho.

The discovery of this 80-carat, D-colour Type-II diamond comes less than a month after the firm announced the recovery of a 114-carat stone from the same mine. And two years after Gem Diamonds found an “exceptional” 357-carat rock, which sold for $19.3 million.

The stock soared on the news and was trading 6.25% higher in London to $89.25 pence at 3:18PM GMT.

Since acquiring Letšeng in 2006, the company has found four of the 20 largest white gem quality diamonds ever recovered, which makes of the Lesotho mine the world’s highest dollar per carat kimberlite diamond operation.