Russian mining giant Alrosa is placing 19 rough diamonds under the hammer, including a 401.97-carat stone as part of an international rough diamond auction and polished diamond tender.
The 19 lots, which have a total weight of 1,098 carats, are the property of Alrosa and JSC Almazy Anabara.
The polished diamond tender will feature 28 diamonds, five of which are more than 5 carats, with the largest round-cut diamond weighing 40.25 carats.
Sales are being held from August 23 to September 3 in Vladivostok, Russky Island. Auctions results will be announced on September 3.
A total of 30 companies from Hong Kong, Israel, India, the US, Belgium and Russia are expected to participate in the auction.
The auction is being held in the run up to the second Eastern Economic Forum to be held in Vladivostok on September 2 to 3, said Alrosa.