ALROSA posted a 33-percent jump on the year in rough and polished diamonds in May to $472.1 million.
Revenue from rough diamond sales amounted to $467.6 million, while polished diamond sales were $4.5 million.
However, in the January-May period, ALROSA's rough and polished diamond sales were down 5 percent on the year-earlier period to $2.13. Rough diamond sales were $2.09 billion, while polished goods were $44.3 million.
Commenting on the 5-percent reduction in January-May this year, ALROSA Vice President Yury Okoemov said that this was a result of the company selling a large amount of high-priced rough diamonds from previously accumulated stocks early in 2016.
"This year, the share of small-size, inexpensive rough diamonds in total sales is higher, which, above all, is related to the composition of stock as at the start of the year," the firm said in a statement.
He also noted a revival in demand for inexpensive rough diamonds in India, which showed a noticeable slowdown late last year as a result of a monetary reform.