Formation of Diamonds

Diamonds are made of carbon that crystallized under conditions of extreme temperature and pressure. They were formed millions of years ago in molten rock within the Earth at depths greater than 160 km. After their formation, diamonds were carried up to the surface of the Earth in rising magma by strong volcanic activity. When the magma cooled, cone-shaped pipes of bluish rock called kimberlite were left behind. Over the years, wind, rain, snow and ice eroded the kimberlites and released diamonds and indicator minerals (small particles indicating the presence of diamonds). Advancing and receding glaciers sometimes dispersed and transported the eroded materials hundreds or thousands of kilometres away.

(You can view an animated version of the formation of diamonds below.)

Some diamonds can be found in these secondary deposits of washed-away materials called alluvial deposits. However, the primary source of these highly prized gemstones is the kimberlite itself. To find these diamond-bearing rocks, geologists combine the results of the chemistry of indicator minerals, regional ice advance studies and geophysical analysis.To date, over 500 kimberlites have been found in Canada and many lie in our remote northern areas (click here to see the location of kimberlites in Canada).

Exploration for diamonds is ongoing in the territories and several provinces, ensuring that Canada will be a world-leading diamond-producing nation for many years to come.

More information on the origin of diamonds is available at the following sites:

• Diamond Pipeline (De Beers)

• Return to Canada: A Diamond-Producing Nation