Koornneef wanted to know where the diamonds in the nearby Venetia Mine came from, and says she was surprised by the results of her study. She did not just find one way that diamonds in this area originated. She found two separate waves of emerging gems, one 3 billion years ago, and the other 1.1 billion years ago. “They were quite different from each other,” she says. “Completely different signatures.” The older diamonds formed when the Zimbabwe Craton, a 3.5 billion-year-old piece of earthly crust, tore apart and crashed into another craton. That process was gentle compared to the boiling chaos that created the second set of diamonds from the mine. That bygone hellscape was so volcanically active and large that it has a name: the Umkondo Large Igneous Province. Now, only the geological records hint at this long-lost, magmatic past.