Diamond

Amazing Story - Part 1

Crystallized serendipity

When you touch a diamond you are in contact with the origins of the Earth. Your touch is a locus where atomic essence, tremendous geological forces and persistent human effort coincide.

The Canadian Museum of Nature received seven diamonds from the first diamond mine in Canada, in operation since late-1998. This invaluable addition to Nature's Earth Sciences Collection was a gift of the mine's owners and operators: BHP Diamonds Inc., Dia Met Minerals Ltd., Chuck E. Fipke and S. Blusson. Fipke and Blusson can also be credited with making the first discovery of an economically exploitable primary source of diamonds under Canadian soil.

These two geological sleuths put their knowledge and tools to work to find the metaphorical needle-in-a-haystack (without even being sure that there was a needle, or even a haystack). But first, a complex of many other impossibly coincidental circumstances had to occur millions upon millions of years before. For starters, the diamonds had to form.

The needle: diamond crystals

Most diamonds probably formed relatively soon after the formation of the Earth, during or shortly following the formation of the continents. Canada's diamonds formed under archons, which are thick and stable parts of the crust that are older than 2.5 billion years. Here, in the mantle 200 km or more beneath the (current) surface, a very particular balance of high pressure (about 5,520,000 kpa, or 800,000 psi) and high temperature (from 1100°C to 1482°C, or 2012° to 2700°F) allowed diamond to crystallize from carbon.

Diamond is made of carbon atoms that have been arranged in a very tightly bonded and compact structure. This structure is made possible by the unique characteristics of carbon atoms, combined with the extreme conditions of the location. While diamond can tolerate some impurities (like oxygen), and they are common, too much will prevent the mineral from forming. Also, changes in temperature or pressure can cause the atoms to reabsorb or realign, thereby 'disassembling' the diamonds.

From the needle to the haystack...