London: Gem Diamonds has recovered two rough diamonds larger than 100 carats at its Letšeng project in Lesotho amid a shift to a more lucrative section of the mine, the company said Monday.

The heavier of the two, at 151.52 carats, is a yellow, type I diamond. The other is a higher-quality, D-color, type IIa stone weighing 104.73 carats. While Letšeng is known for producing high-value large diamonds, it yielded only five 100-carat-plus stones in 2016 — compared with 11 in 2015 — dragging down Gem Diamonds’ revenues by 22% and its average selling price for the year by 26%.

The company is hoping to reverse the trend with its latest discoveries. In April and May, Gem Diamonds found three large D-color, type IIa rough diamonds weighing 80.58 carats, 98.42 carats and 114 carats respectively. The smallest of these was one of the highest-quality diamonds in the Letšeng mine’s history, the company said.

Mining at Letšeng shifted to the higher-grade K6 portion of the project’s main pipe in the second quarter, improving the rate of large-diamond discoveries, Gem Diamonds explained.