To purchase this space contact Gordon

The US Treasury has extended sanctions to Russian diamond miner Alrosa PJSC, potentially cutting off about 30% of the world’s supply of rough stones.

Clients of Alrosa as well as other counterparties must stop all dealings with the state-controlled Russian miner by May 7, according to a license from the US Office of Foreign Assets Control. The company’s shares fell as much as 6.2% in Moscow trading. Alrosa declined to comment.Advertisement

Alrosa produces about the same amount of gems as De Beers, the iconic diamond company that had a monopoly until the start of this century. Russia vies with Botswana as the world’s biggest diamond producer, while the US is the industry’s most important market, accounting for about half of all sales.

The US restrictions tighten the screws on Alrosa as the risk of cross-sanctions threatens to deter buyers in other regions. The European Union and the U.K. previously imposed sanctions on the miner following Russia’s invasion of Ukraine. The main markets for Alrosa, which employs about 32,000 people, are the US and Asia, including India.Advertisement

Last month, US-based jewelers Tiffany & Co. and Signet Jewelers Ltd. said they were stopping buying new diamonds mined in Russia as pressure builds on companies to cut the nation’s products from their supply chains.