We've looked at pearls; now it's time for diamonds. Let's do this.
In the center of tectonic plates are places that remain still and stable as thinner edges of the earth’s crust stretch and swirl around them. These places are called cratons, and they extend hundreds of miles below the surface, ancient bedrock as reliable as Atlas, pushing into the dense mantle that surrounds the core. If you were a mole person, capable of tunneling about 100 miles down into one of these cratons, and you lived sometime between 1 billion and 3.3 billion years ago, you might notice that the temperature and the pressure was just [...]