200-Carat Diamonds Are Evidence That New Mining Techniques to Protect Exceptional Stones Are WorkingOctober 18, 2013
Mining company Alrosa just unveiled another mammoth diamond — a 235.16-carat beauty — from its Jubilee Diamond Pipe in Russia’s Siberian republic of Yakutia. Only a month ago, competitor Lucara found a 257-carat rough diamond at its Karowe Mine in Botswana. It was the 14th rough diamond larger than 100 carats unearthed by Lucara this year.
Are the mining companies experiencing a run of good luck, or are other factors contributing to the increasing frequency with which these ultra-rare weighty gems are being plucked from the earth?
Alrosa explained that recent technological advancements made at its production facility have improved recoveries and reduced breakage of exceptionally large stones.
Typically, the ore containing the rough diamonds goes through many stages of crushing and processing before it can be sorted and classified. Although diamond is the world’s hardest material, is can be brittle. In the past, larger diamonds could be inadvertently fractured by the heavy machinery during processing.
Said Alrosa, “The integrity of [the 235-carat] diamond is a testimonial to the well-established workmanship of miners and dressers, and a high level of technological equipment.”
The Alrosa diamond is of gem quality, octahedral in shape, transparent and has a yellow hue. Its dimensions are 42 millimeters by 26 millimeters by 28 millimeters. Experts believe the gem is worth between $1.5 million and $2 million. Lucara simply described its massive find as “beautiful and clear.”