Saturday, the Russian diamond mining and production company Alrosa announced that it will offer a rare 242-carat rough diamond for sale at an auction in Dubai on Mar. 22. The rock is one of the largest gemstones extracted in the current century.

According to the Emirati newspaper Al-Bayan, the diamond is the size of a small egg or a golf ball.

In statements, the Head of Sales at Alrosa Evgeny Agureev said, “Rough diamonds, which potentially allow for cutting a polished diamond larger than 100 carats, are extremely rare in nature."

Agureev noted the rarity of having such diamonds at auctions. "Even less often are such gems tendered,” he added.

The last time Alrosa offered a rough diamond of this size for sale at an open auction was five years ago.

Russian law states that diamond miners must offer 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.