VANCOUVER (miningweekly.com) – Russian mining major Alrosa has recovered a formidable 136.24 ct diamond from the Nyurbinskaya kimberlite pipe, in Yakutia, Russia, the company revealed on Monday.
The gem-quality rough diamond, which is classified as a 3 Black Makeable 1 Сolour, measured 29.32 × 23.88 × 21.9 mm and is one of the largest stones recovered in the Nyurbinskaya pipe’s history, Alrosa advised.
The gem stone has a combination-form translucent colourless part of a crystal with a columnar interlocking sculpture. The stone contains graphite and sulphide composition.
The Nyurbinskaya kimberlite pipe often delivers large precious gems, including a 241.21 ct rough diamond recovered in June. Alrosa, the world’s largest diamond producer by volume, said the latest significant stone recovered has not yet been named.
After discovery in 1996, the Nyurbinsky openpit mine was put into operation in 2001. As of January 1, 2015, the kimberlite pipe contains Joint Ore Reserves Committee-compliant reserves totalling 36.9-million carats.
The Nyurba mining and processing division is one of Alrosa’s youngest enterprises, operating the Nakyn orefield containing the Nyurbinsky and Botuobinsky openpit mines, and two eponymous alluvial placer operations. The division accounted for about 20% of Alrosa’s output in 2015, the company advised.