Gem Diamonds has released a trading update for the first half of 2011, with detailed financial results expected August 19. According to the trading report, record prices for rough diamonds were seen in H1.

Diamonds produced by Letseng achieved a record average of $3,052 per carat, as compared to $1,728 per carat in the same period last year. There were 30 rough diamonds that fetched more than $1 million. During H1, Letseng produced 295 rough diamonds that were larger than 10.8 carats and 105 that were worth more than $20,000 per carat.

The Ellendale mine managed a record average of $4,045 per carat for its fancy yellow diamonds, as compared to $2,588 per carat last year. An agreement was made to raise the prices of Ellendale's fancy yellow diamonds that are sold to Tiffany & Co. by 24.73%.

Gem Diamonds has said that it is nearly finished with a pre-feasibility study for the expansion of Letseng in Lesotho. In addition, the board approved first stage development at the Ghaghoo Mine (formerly Gope) in Botswana.

The company also reported zero major environmental and community incidents in 2011 and a group-wide All Injury Frequency Rate of 4.55, which is significantly lower than the 2011 AIFR threshold.

The prices for yellow diamonds sold to Tiffany & Co. will rise by nearly 25%