The company has named the diamond "70 years since Victory in the Great Patriotic War", which is expected to be auctioned for around $430,000.
The latest find is the fourth one of this size found in the diamond field in past two years, UK based diamond specialist Marlow’s Diamonds said.
The surface of the diamond contains discal crack, which is filled with sulphide and graphite.
Marlow’s Diamonds spokesperson said: "Considering that a quarter of natural diamonds in the world come from Russia, it’s not surprising that Alrosa has found another huge diamond.
"It is, however, surprising that the Yubileynaya diamond field continues to be so profitable for the company."
