PJSC ALROSA, the world leader in diamond mining, announces the recovery of a 241.21-carat rough diamond from Nyurbinskaya pipe.
It is one of the largest rough diamonds recovered in the Russian Federation and the third largest among those found at Nyurba Mining and Processing Division.
The crystal measures 38.64 mm by 27.34 mm by 25.46 mm, and is translucent with a grey hue. Traces of dissolution–etching channels and caverns–are observed on the surface. The intermediate and peripheral zones contain large cracks, one of which is ferruginized. The crystal contains graphite and sulphide inclusions. The diamond is 4 Black Clivage/Makeable 2 colour.
Nyurbinsky open-pit mine was put into operation in 2001. Identified reserves of the diamond pipe under JORC as of January 1, 2015, amounted to 36.9 million carats.
Nyurba Mining and Processing Division is one of ALROSA’s youngest enterprises. It operates at the Nakyn ore field and develops Nyurbinsky and Botuobinsky open-pit mines, and two same-name alluvial placers. Its share in ALROSA Group’s production totaled 20% in 2015.