Alrosa's (MCX:ALRS) International mine produced this month the largest gem-quality diamond seen in the past two years.
In a press release, the world's top diamond miner by output revealed that the stone weighs 118.91 carats, displays a light yellow overblown, has salient edges, one of them with cleavage, and has small inclusions in the central zone.
The International deposit was first discovered in 1969. By the time it was fully developed, reserves were estimated in more than 100 million carats"This crystal is unique as it has a large clean area despite the inclusions in the center - this makes it a gem-quality diamond," Evgeny Agureev, director of the united selling organization at Alrosa, said in the media brief. "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 edges."
Agureev said that a similar rock - a 109.61-carat diamond - was mined at the International pipe in the summer of 2017.
Given that the new gem was mined on April 16, 2019, the eve of the launching of Alrosa's Zarya deposit, it will carry the name of the mine.
The International mine, which reached full production rate of 500 kt/a in 2002, is located 16 kilometres south-west of the town of Mirny, in east-central Russia. Mineral resources in the measured category are 20,157 kct, while in the indicated category are 29,608 kct. Approved reserves are characterized by a high diamond content in ore, about 7-8 carats per tonne on average.