I am a mineralogist/crystallographer who studies the crystal structures of rock-forming minerals that are significant constituents of the Earth. My research focuses on crystal structures and elastic properties of silicate and oxide minerals of the deep mantle. Initially, I did this by theoretical calculation and prediction of hydration sites, and predicted that wadsleyite, the first pressure polymorph of olivine, could incorporate more water that the Earth’s oceans. Through collaboration with the Bavarian Institute for Experimental Geophysics and Geochemistry at University of Bayreuth in Germany, I have been able to synthesize these minerals and measure their elastic properties as a function of hydration at temperature and pressure. We find that the silicate minerals of the interior contain most of the planet’s water as hydrogen dissolved in these oxygen minerals.