Russia's Alrosa to offer a rare 242-carat rough diamond at Dubai auction

MOSCOW (Reuters) - Russian state-controlled diamond producer Alrosa will offer a rare 242-carat rough diamond - one of the biggest gem-quality stones it has mined this century - for sale at a Dubai auction on March 22, the company said on Friday.

The crystal-clear diamond is the size of a small egg. Alrosa, the world's largest producer of rough diamonds, competes with Anglo-American unit De Beers.

"Rough diamonds, which potentially allow for cutting a polished diamond larger than 100 carats, are extremely rare in nature. Even less often are such gems tendered," Evgeny Agureev, Alrosa's head of sales, said in a statement.

Alrosa last offered a rough diamond of such a size at open auction five years ago. Russian law states that the miner must first offer its rough diamonds larger than 50 carats to the Gokhran state repository.

The diamond was held back until now to mark Alrosa's 100th international auction.

The auction price will start from $2 million.

(Reporting by Polina Devitt; editing by Alexander Marrow and Mike Collett-White)