Before booting my laptop, I knew that diamonds are carbon transformed by extreme heat and pressure into the hardest, clearest mineral on earth. That because of their rigid tetrahedral molecular structure—a triangular pyramid with four faces—a diamond can be cut only by another diamond or a laser.

I knew that the sparkly little rocks are pricey as hell. And that they create an eyeful of bling.

That was about it.

Every thirty minutes I’d interrupt my research to phone Katy. Each time her phone would roll to voice mail. Uneasy, I’d dive back onto the Internet.

In between dialing, I learned the following.

It takes forty-four to fifty kilobars of pressure at a minimum of a thousand degrees Celsius to change carbon into diamond. I understood the temperature but wasn’t sure the exact nature of a kilobar.

The appropriate combo of heating and crushing existed a few billion years ago at depths of eighty to a hundred and twenty-five miles in rock formations called cratons, dense old slabs of continental plate.

Later, underground volcanoes sent magma—or molten rock—minerals, rock fragments, and occasionally diamonds bubbling up through the cratons. The mixture expanded and cooled along the way to form either carrot-shaped pipes to the surface, or wide flat underground structures called dikes. It then solidified into rock called kimberlite.

Most diamondiferous kimberlites are associated with cratons from the Archean era, an early part of the Precambrian, when the earth was much hotter than today. Much hotter. Many kimberlite pipes lie underneath shallow lakes formed in inactive volcanic craters called calderas.

So. To score diamonds, you locate a pipe rising from a really old craton. Piece of cake, right? Wrong. The buggers are incredibly hard to find.

That’s where Chuck Fipke and Stu Blusson came in. Both knew that the Slave craton, which underlies the Northwest Territories from Great Slave Lake in the south to Coronation Gulf on the Arctic Ocean, is one of the oldest rock formations on earth. And they developed an effective technique to explore it.

Fipke understood the significance of indicator minerals, the traveling companions of diamonds. Those in kimberlite include calcium carbonate, olivine, garnet, phlogopite, pyroxene, serpentine, upper mantle rock, and a variety of trace minerals. Fipke focused on the trifecta of chromite, ilmenite, and high-chrome, low-calcium G10 garnets.

Blusson understood the significance of glacial movement during the last ice age. He reasoned that, after eroding a kimberlite pipe, a retreating glacier would leave a debris path containing diamond indicator minerals. Track the path to its source, he argued, and you’ll find the pipe.

Fipke and Blusson spent a decade scouring the tundra, mapping, surveying, coring, and collecting when temperatures were bearable, analyzing samples in their lab when the weather was too harsh. Everyone in the mining world thought they were nuts.