Polished Diamond Stones

From Mine to Market


Over one billion years ago, the North’s diamonds formed deep within the earth. Volcanic eruptions of molten rock, known as kimberlite, which occurred approximately 55 million years ago in Canada’s remote tundra, would bring these precious gems to the surface. The molten rock would then cool and solidify. Over time, the tops of these extinct volcanoes would succumb to erosion including glaciation just 5,000 years ago, which would carve out portions of this softer rock (the kimberlite is surrounded by ancient Canadian Shield granite) and transport it several hundred kilometres.

The challenge for geologists was to trace the rare tiny kimberlite indicator minerals back to its source, the kimberlite pipe. Once found, exploration companies sample the pipes for potential. Very few kimberlites contain diamonds and even fewer are economic to mine.


Once a company deems its stake viable to mine, and all of the proper permits, licences and Agreements are negotiated and signed, construction of a major mine site can begin. However, there are no roads to these remote arctic locations and it is too costly to deliver large-scale supplies and equipment by plane. Even when mining operations begin, this same challenge will exist for the duration the mine’s life.

To address this, each year experienced NWT businesses and contractors use modern techniques to build and maintain an ice road strong enough and long enough to allow trucks to resupply these remote mine sites. The Tibbitt to Contwoyto Winter Road consists of 400 to 600 kilometres of groomed frozen lakes and portages, and is open for six to eight winter weeks a year (late January to early March). A very short period of time in which trucks resupply the mines with all the large-scale equipment and supplies they need for the upcoming year.

Mining and processing activities at each mine are continuous 24/7 operations. Mined ore gets crushed, scrubbed and ground to release diamonds from the surrounding kimberlite. Diamonds are then separated from non-diamond material using wet and dry particle x-ray sorters, drier, and grease table. As diamond mining doesn’t use any harsh chemicals or produce any harmful by-products from processing, mines can safely store non-diamond material (processed kimberlite and rock) before returning it back to the land as part of reclamation.


Rough diamonds from the mines are flown to Yellowknife for basic sorting, which includes cleaning and sizing and basic sorting of stones, as well as the division of product for various marketing channels, and government valuation for sale to Approved NWT Diamond Manufacturers.

There are two Sorting and Valuation Facilities in the capital city. Opened in 1999, Dominion Diamond Corporation's (formerly BHP Billiton) Sorting and Valuation Facility sorts EKATI diamonds prior to their sale to manufacturers and traders through Dominion's sales office in Toronto, Ontario. The second facility belongs to Diavik Diamond Mine, where Diavik diamonds undergo sorting and are then divided 60/40 between the joint venture partners (Rio Tinto and Dominion Diamond Corporation). The Diavik facility also sorts the De Beers diamonds from Snap Lake mine (under contract).


The secondary cutting and polishing industry is also a viable and important economic venture for the NWT. Innovative manufacturing facilities were built in Yellowknife, bringing some of the world's most experienced and skilled diamond cutting and polishing craftsmen to oversee employees, many of whom are NWT residents, as they turn NWT rough stones into polished diamonds of the highest quality in the world.

The key to developing diamond manufacturing opportunities is reliable access to quality rough diamonds. Agreements and arrangements with the three operating mines guarantee Approved NWT Diamond Manufacturers have access to rough stones for the purpose of manufacturing diamonds in the NWT.

In the pursuit to authenticate NWT diamonds, the GNWT developed the world’s-first polished diamond certification program, the GNWT Diamond Certification Program. The diamonds certified by this program are guaranteed as mined, cut and polished in the NWT and adhere to the highest ethical standards from mine to market.


Usually, the final step before a diamond is sold is production. Designers around the world work with diamonds every day to create beautiful pieces of jewellery, art and fine crafts and more.

Diamonds from Canada, and in particular, those that carry the distinction of GOVERNMENT CERTIFIED CANADIAN DIAMOND™, are sought out by the world’s finest jewellers and designers to compliment their masterpieces.


The final step in the Mine to Market process is the sale. People all over the world covet diamonds, and perfectionists seek out the world’s best, like a GOVERNMENT CERTIFIED CANADIAN DIAMOND™ from Canada’s Arctic.

NWT diamonds, and in particular those that are government certified, are as pristine and beautiful as the natural surroundings they were formed in over a billion years ago. Whether sold in a perfect and unique setting, incorporated into a piece of art, or sold loose to allow the purchaser to turn it into their own custom piece of jewellery or art, they are truly world class.