A mining company has announced plans to sell a collection of what it says are the most valuable diamonds ever cut in Russia.
The largest in the collection is a 51.38-carat round cut diamond. It was produced by Russia's Alrosa company as part of a special collection called Dynasty.

The state-run Alrosa said the five-piece collection was named after the Romanov dynasty, which ruled Russia for 300 years. It is also meant to honor Russian ruler Peter the Great, who built the city of St. Petersburg. The company said Peter the Great started the country's first diamond factory early in the 18th century.

Alrosa calls the biggest piece "the purest of all large diamonds manufactured throughout Russian jewelry history." The 51.38-carat diamond is 2.5 centimeters in diameter.

The Dynasty collection was created from one 179-carat rough diamond discovered in 2015 in Russia's far eastern republic of Sakha. It took a team more than a year and a half to complete the five polished diamonds.
The project marked progress for Alrosa. The company is known for discovering rough diamonds, but not cutting and polishing them. It said the process "combined modern technologies with the secrets of jewelers of the Russian Imperial Court."

Russia is considered the largest diamond producer in the world. Alrosa and British-based diamond company De Beers produce about half of the world's rough diamonds.

Alrosa's president said at a launch event in Moscow that the collection is expected to go on sale as a set in an online auction in November.
The company expects to get at least $10 million for the diamonds, which are currently being shown in Moscow.

The collection will also travel to Israel, Hong Kong and the United States to give possible buyers the chance to get a close look.
I'm Bryan Lynn.