RAPAPORT... Gem Diamonds' revenue dropped in the third quarter as the miner sold fewer high-value stones from its lucrative Let??eng deposit in Lesotho.Sales came to $47.3 million for the three months ending September 30, the company reported Thursday - a 22% decline from a year earlier. The average selling price decreased 28% to $1,589 per carat.While prices were robust on a like-for-like basis, the company had limited supply of large and high-quality diamonds, which command a higher price per carat.The top-selling items for the quarter were a 4.41-carat, light blue diamond, which fetched $88,889 per carat, and a 65-carat, white, type IIa stone, which went for $47,574 per carat. In the same quarter of 2020, Gem Diamonds' average price got a boost from the sale of the 439-carat Let??eng Icon. Furthermore, revenues from diamonds worth $1 million or more fell to $12.2 million in the third quarter of 2021, compared with $25.6 million a year earlier. The miner sold six stones in that value range, compared with seven a year before."Diamonds recovered were of a relatively lower quality for Let??eng's normal run-of-mine production," said Gem Diamonds CEO Clifford Elphick Thursday. "Notwithstanding that, prices achieved for these goods were strong, reflecting the continued good demand and market prices paid for Let??eng-category diamonds."The company registered solid prices at its September tender, reflecting "a continued recovery of the diamond market, which was supported by strong consumer demand," it explained. A trial viewing of goods in Dubai that month saw a good attendance and competition, boosting prices, it added.Meanwhile, total sales volume climbed 9% to 29,782 carats. Production slipped 20% to 23,435 carats because of several operational issues at the mine. As a result, the company has reduced its full-year output forecast to between 110,000 and 114,000 carats, compared with its previous plan of 123,000 to 127,000 carats.Its sales guidance has also declined to a range of 103,000 to 107,000 carats, versus a previous outlook of 119,000 to 123,000 carats.Revenue for the first nine months of 2021 increased 12% year on year to $151.3 million, as positive figures in the first half outweighed the third-quarter slowdown. Sales volume jumped 20% to 84,906 carats, while the average price decreased 7% to $1,782 per carat.Image: A rough diamond from the Let??eng mine in tweezers. (Gem Diamonds)