JOHANNESBURG (miningweekly.com) – The Jubilee (Yubileynaya) pipe at Aikhal yielded two gem-stone quality diamonds of more than 100 ct each last year for the mining and processing division of Russian miner Alrosa.
The smallest of the two stones is a 108.34 ct rough diamond, measuring 23 mm by 20.56 mm by 17.86 mm. The other stone is a 163.11 ct diamond measuring 26.67 mm by 25.59 mm by 22.4 mm.
A third large stone, an 82.82 ct octahedron rough diamond, measuring 23.28 mm by 19.06 mm by 18.8 mm by 15.94 mm, was also recovered.
"Simultaneous extraction of three large rough diamonds, two of which are over 100 ct, within such a short period of time is a one-off event especially when it comes to gem-quality diamonds. As a rule, only five to ten similar stones over 100 ct may be recovered within a year, and they are always in great demand at auctions,” United Selling Organisation Alrosa director Evgeny Agureev said in a statement this week.
The Jubilee pipe is traditionally Alrosa’s leader in the recovery of large diamonds. So far, the pipe has yielded 20 rough diamonds over 50 ct this year.
The pipe has produced 6.57-million carats of rough diamonds in the first nine months of the year, or about 22% of Alrosa’s total diamond production for the period.
Jubilee was discovered in 1975 and ranks among the largest primary diamond deposits in the world. It is located in close vicinity to the Aikhal settlement and 485 km north of Mirny. Openpit mining at Jubilee started in 1989.