Researchers unearth ‘tectonic events’ that formed Canadian sapphires – Technology & Science

Treasure-hunting Canadian researchers say they have figured out how to find sapphire deposits by identifying the exact sequence of geologic events that create the sparkling gemstone.

To date, Canada’s only significant deposit of sapphires is one that was discovered near Kimmirut, on southern Baffin Island, Nunavut, in 2002.

The quality of the Beluga sapphires produced from that deposit can be so high that they don’t have to be heated to intensify their colour and clarity, unlike nearly 99 per cent of sapphires. 

They’re good enough that 48 of them, totalling 10.19 carats, were used to adorn a ceremonial brooch presented to Queen Elizabeth earlier this month by Governor General David Johnston to mark her sapphire (65th) jubilee on the throne.  

The Geological Association of Canada says the geological setting of the region is similar to that of the gem-producing areas of Kashmir and Myanmar, where some of the world’s most valuable stones originated.

But would-be gemologists who want to explore for more are stuck between a rock and a hard place: sapphires are buried deep in inhospitable Arctic terrain. It’s an expensive and onerous proposition to mine them.

That’s why mineralogists at the University of British Columbia studied this gold mine of sapphires.

“The quality and the abundance of sapphire in the Kimmirut area is just off the hook — it doesn’t come close to anything else in Canada,” says Philippe Belley, a grad student in the Earth, Ocean and Atmospheric Sciences at UBC.

Belley, along with associate professor Lee Groat and colleagues, sought to explain how those deposits were formed.

“We found that three pressure and temperature events were all necessary to create sapphires in this type of rock composition,” Belley told CBC News.

Sapphire crystal, 3.6 cm, and…

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