Two tear-shaped black diamonds , with a combined weight of 100 carats , hang down from the middle .
一对重达100克拉的水滴状黑钻挂坠在中间。
Its " new normal " peak output from 2011 onwards , mr penny says , will be about 40m carats annually .
彭尼表示,从2011年起,公司“新的正常”最高产出将约为每年4000万克拉。
But petra reckons the mine still has another 20 years of production in it and plans to extract at least 1m carats a year .
但是petra认为该钻矿仍可继续开采20年,并计划每年至少开采1百万克拉。
The diamonds are washed and sorted by size , clarity , shape and quality ; then , rather than being sent to be sold around the world , they are wrapped in paper and whisked away to a vault - about three million carats worth of gems every month .