Gaborone: De Beers said its rough diamond prices fell 5 percent this year even as the diamond market showed signs of a vast improvement.

Diamond prices declined from January to November, while prices of other commodities in the conglomerate’s portfolio rose significantly, Mark Cutifani, CEO of Anglo American, the parent company of De Beers, said in an analyst presentation.

“The diamond sector, on average, saw a strong recovery of value in the first quarter, recovering much of the lost ground from 2015, alongside the wider mining sector,” Kieron Hodgson, an analyst at Panmure Gordon & Co. wrote in a note preceding Anglo’s presentation. “While the absolute performance of diamonds has lagged peer commodities, we believe the longer term fundamentals remain robust for price appreciation, albeit with lower volatility.”

De Beers rough price index, which monitors prices on a like-for-like basis, fell 6 percent in the first half, with most of the decline seen in January, a presentation by Bruce Cleaver, De Beers CEO showed. That indicated the index increased an estimated 1 percent in the second half, excluding this week’s final sight of the year.

Despite lower prices, De Beers is expected to drive growth at Anglo American this year as diamond sales grew in the first half whereas revenue fell from each of its other core commodities – coal, platinum and iron ore.

De Beers sales reached $5.16 billion year-to-date November, which, even excluding this week’s sight, far exceeds rough sales of $4.13 billion reported for 2014. The December sight ends Friday, with the sales value scheduled to be reported by De Beers on Tuesday.