Diamonds travel to Earth’s surface on fizz

Science : New lab tests demonstrate how diamonds embedded in molten material deep beneath Earth’s surface can survive volcanic eruptions. A study conducted by Kelly Russell of the University of British Columbia in Vancouver, Canada, shows that molten rock that is rich in carbonate—such as kimberlite, which often contains diamonds—releases its carbon dioxide when it comes into contact with silica-rich minerals. The dense magma, now made buoyant, surges upward from Earth’s upper mantle, bumping into overlying rocks that contain more silica, which accelerates the carbon dioxide release. The chemical reaction that drives the release is largely self-sustaining, with the necessary heat being supplied by the crystallization of other minerals such as olivine. The frothing kimberlite lava could travel to Earth’s surface from a depth of as much as 120 km in about 3 to 8 hours, according to Russell’s estimates.