The Unexpected Origins of Big Diamonds

23.16 carat pink diamond unearthed from the Williamson Mine in Tanzania. Image courtesy of Petra Diamonds.

Dr. Evan Smith, Ph.D., GIA research scientist, has dedicated his work to methodically characterizing the inclusions found in rare diamonds. In this video presentation recorded at the 2017 JCK Las Vegas show, Smith shares his findings on the unexpected origins of big diamonds and what their characteristics tell us about the earth.  

“Next time you look at a diamond, I hope you see it not only as a beautiful, valuable piece of gemstone; [you should also know that] diamonds are some of the most scientifically valuable samples of our earth,” Smith said. In this video, he explains that as diamonds form more than 100 miles below the earth’s surface, they often trap mineral inclusions that reveal the chemistry of the earth’s mantle. 

Diamonds are some of the most scientifically valuable samples of our earth.
Dr. Evan Smith, GIA research scientist

Smith’s study on a 400 carat diamond found in Angola was the December 2016 cover story of Science magazine. Big diamonds such as this were the basis for his research in part because the origins of big stones are relatively unknown to scientists. He examined a variety of large, unique diamonds with similar characteristics. The diamonds were all similar to the Cullinan diamond, the largest gem quality diamond ever found. They were large and inclusion poor, typically without mineral inclusions; pure type IIa diamonds low in nitrogen; irregularly shaped and resorbed with surfaces rounded and dissolved. These characteristics gave rise to their name – CLIPPIR diamonds.

Origins of Big Diamonds

An expert in diamond geology, Smith received his bachelor of applied science and master of engineering from Queen's University and a Ph.D. in geology from the University of British Columbia. He performed his postdoctoral research fellowship at GIA in 2015.