(Reuters). Moscow-listed shares Alrosa, a state-controlled miner of diamonds, fell 5% Friday morning following the US imposing sanctions against the company. This was in response to Russia trying to eliminate additional revenue streams for its budget.

Alrosa, which is also the biggest producer of rough diamonds in the world, competes with Anglo American De Beers unit (LON) produced around 30% of the world’s total carats. It was 32.4 million in number. It exports mainly to India and Belgium.

Alrosa was placed on Thursday by the United States on the Specially Designated Nationals list. This effectively bans any sanctioned firm from the U.S. bank system, and also prohibits it trade with Americans. It complicates operations on the international diamond market.

Alrosa didn’t respond to Reuters’ requests for comment.

This company employs 32,000 people. It mines the rare stones in Russia’s Far East, which is difficult to access and has few opportunities for other jobs.

In a statement, the U.S. Treasury Department’s Office of Foreign Assets Control announced that diamonds were one of Russia’s 10 top non-energy exports. Exports to 2021 will total over $4.5 Billion.

Russia had sent thousands of troops to Ukraine in what it called an “special operation” on February 24, but the OFAC put Alrosa under severe sanctions. This limited its ability in America to issue new debt.

Alrosa holds a 41% interest in Catoca diamond production company, Angola. But Catoca is not subject to the U.S. sanction.