Fluids trapped within the stones are helping researchers reconstruct the deep history of the continent, and eventually maybe others.

People have been finding loose diamonds across the United States and Canada since the early 1800s, but for the most part, no one knows where they came from. It was not until the 1990s that geologists tracked down the first commercial deposits, on the remote tundra of Canada’s Northwest Territories. Yaakov Weiss, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, is investigating the origins of these rich diamond mines.

“After a diamond captures something, from that moment until millions of years later in my lab, that material stays the same. We can look at diamonds as time capsules, as messengers from a place we have no other way of seeing.”