Alrosa has found a 241.21 carat diamond, one of the largest ever found in Russia.
The stone was recovered from the Nyurbinskaya pipe, and measures 38.64 millimetres by 27.34 millimetres, and is translucent with a grey hue.
“Traces of dissolution–etching channels and caverns–are observed on the surface,” Alrosa said.
“The intermediate and peripheral zones contain large cracks, one of which is ferruginised. The crystal contains graphite and sulphide inclusions. The diamond is 4 Black Clivage/Makeable 2 colour.”
Earlier this year the miner found a 122 carat diamond at its Jubilee pipe.
The mine has been in operation since 2001