RAPAPORT... Alrosa's sales soared in December to their highest level in almost three years as rough demand continued to gain momentum.Diamond revenues rose 43% year on year to $521.6 million, with rough sales jumping 34% to $470.3 million - totals the Russian miner hasn't exceeded since March 2018, according to Rapaport archives. Polished sales more than quadrupled to $51.2 million from $11.6 million a year earlier, reflecting the company's $26.6 million sale of the 14.83-carat Spirit of the Rose diamond at Sotheby's, Alrosa reported Wednesday.The company sold some of the rough inventory it had accumulated during the coronavirus downturn, benefiting from the robust market during December, deputy CEO Evgeny Agureev noted. The final month of the year is typically a time for manufacturers to restock following pre-holiday polished sales to retailers. "Strong sales of rough and polished diamonds by Alrosa in December were driven by the continued strong demand from the midstream, as well as by one-off factors," Agureev said, referring to the Sotheby's auction, which took place in Geneva in November. "We expect January sales to return to their average for this period, and figure on stable demand and sales during the first quarter."Diamond sales for the full 2020 year dropped 16% to $2.8 billion, as the collapse in demand during the second quarter outweighed the second-half recovery. Revenue from rough fell 19% to $2.65 billion, while polished sales more than doubled to $149.7 million from $64.7 million in 2019, reflecting Alrosa's acquisition of Russian cutting house Kristall.Alrosa's January contract sale, its first of 2021, begins this Friday.Image: Rough-diamond sorting. (Alrosa)