Diavik Mine Yields 552-Carat Yellow Diamond, the Largest Ever Found in North America

In Canada’s frozen Northwest Territories, just 135 miles south of the Arctic Circle, the Diavik mine unexpectedly yielded a 552-carat fancy yellow diamond, the largest ever discovered in North America. The finding is remarkable because Canadian mines are known to produce high-quality diamonds, but not particularly large ones.

The quarter-pound gem-quality stone, which is the size of a chicken egg, is nearly three times heavier than the previous North American record holder, the 187.7-carat "Diavik Foxfire."

Despite its impressive dimensions, the Canadamark™ diamond rates only 25th on the all-time list of the world's largest rough diamonds, just ahead of the Lesotho's Letseng Star (550 carats) and just behind the Central African Republic's Spirit of de Grisogono (587 carats). The top seven diamonds on the list are all from the continent of Africa, including the granddaddy of them all, the 3,106-carat Cullinan, which was discovered near Pretoria, South Africa, in 1905.

Due to the historic nature of the stone, Dominion Diamond Mines, which owns 40% of Diavik, reported that it will be selecting a partner in the coming weeks to cut and polish it. The task is so risky and complex that only a handful of master cutters are capable of handling the assignment. Dominion expects to achieve a "significant" main stone once the diamond is polished.

Dominion Chief Executive Officer Shane Durgin told Bloomberg.com that it was miraculous that the diamond survived the mining process, which entails passing diamond-bearing ore through crushing machines. The 552.74-carat stone was uncovered during the initial screening process at Diavik’s recovery plant and abrasion markings on the stone’s surface attest to the difficult journey it underwent during recovery.

Measuring 33.74mm x 54.56mm, a diamond of this size is completely unexpected for this part of the world and marks a true milestone for diamond mining in North America and Canadamark™ diamonds overall, the company said in a statement.

Mining companies across the globe have been able to preserve 100-plus-carat diamonds due to improved screening technology that allows them to identify and extract large stones before being smashed.

Back in 2015, we reported how the 187-carat Diavik Foxfire diamond narrowly escaped being pulverized because of its unusual finger-like shape. The elongated diamond was saved when it slipped sideways through the filtering screen.

Credits: Diamond images courtesy of Dominion Diamond Mines. Map by Google.