Alrosa said the rough diamond was light yellow overblown, had salient edges, one of them with cleavage, and small inclusions in the central zone.
The diamond was mined on April 16, which was the eve of the launch of Alrosa's new Zarya deposit at its Aykhal mining and processing plant. The last large stone to be mined at International was a 109.61ct diamond in mid-2017.
Member of the management board and director of Alrosa's United Selling Organisation, Evgeny Agureev, said the stone was unique due to its large clean area despite the inclusions in the centre.
"Well-known hallmarks of the diamonds from the International kimberlite pipe are regular shapes and purity. That is exactly the pipe that most often brings Alrosa regular shape octahedrons with smooth edge," he said.