"The analyses revealed that the stone contains numerous ringwoodite inclusions -- which exhibit a high water content. Furthermore, the research group was able to determine the chemical composition of the stone. It was almost exactly the same as that of virtually every fragment of mantle rock found in basalts anywhere in the world. This showed that the diamond definitely came from a normal piece of the Earth's mantle. "In this study we have demonstrated that the transition zone is not a dry sponge, but holds considerable quantities of water," Brenker says, adding: "This also brings us one step closer to Jules Verne's idea of an ocean inside the Earth." The difference is that there is no ocean down there, but hydrous rock which, according to Brenker, would neither feel wet nor drip water."