Strong Demand Pushes up Revenue at Gem Diamonds

(IDEX Online) - Gem Diamonds says first-half revenue from its Letseng mine, in Lesotho, was up 33%, with what it described as "encouragingly strong demand" and a 38% hike in average prices.

Total sales for the six months to 30 June were $59.5 million, compared to $44.7 million for H1 2025, and the average price per carat was $1,395, compared with $1,008, the London-based miner said in a Trading Update.    

Letseng, the world's highest active diamond mine (at 3,100m above sea level) produces an unusually high proportion of large, high-quality stones and is the worlds' highest dollar-per-carat kimberlite deposit.

During H1 2026 it produced three diamonds over 100 carats, including a 346.99 carat white diamond in June.

The highest per carat price achieved in H1 was $32,908 per carat for a 52.24-carat white diamond.

Eight diamonds sold for over $1 million each, generating aggregate revenue of US$16.1 million.

Gem's CEO Clifford Elphick, noted that mines producing lower quality, small rough had been badly hit by lab growns. 

"Letseng, with its exceptional quality and large diamond recoveries, however, has been less impacted, with encouragingly strong demand leading to an improvement in prices during H1 2026," he said.

Pic shows the 346.99-carat white diamond recovered at Letseng last month.