Fluid in superdeep diamonds may be from some of Earth’s oldest unchanged material

Studying such a pristine piece of early Earth may yield insights about the planet’s formation

diamonds

MANTLE SAMPLES Fluids trapped inside diamonds from Juina, Brazil, (pictured) bear the chemical signatures of primordial rock nearly as old as Earth itself.

Graham Pearson

A surprisingly hardy reservoir of rock left over from just after Earth’s formation still lurks deep inside the planet, according to a new analysis of superdeep diamonds.