March 9, 2021ScienceBlog.com Pierfranco Demontis said in 1988, “Ice becomes a fast-ion conductor at high pressure and high temperatures,” but his prediction was only hypothetical until recently. After 30 years of study, superionic water ice was verified experimentally in 2018. Superionicity may eventually explain the strong magnetic field in giant planetary interiors. What about Earth, whose interiors are also under extreme pressure and temperature conditions? Although three-quarters of Earth’s surface is covered by water, standalone water or ice rarely exists in Earth’s interiors. The most common unit of “water” is hydroxyl, which is associated with host minerals to make them hydrous minerals. Here, a research group led by Dr. Qingyang Hu, Dr. Duckyoung Kim, and Dr. Jin Liu from the Center for High Pressure Science and Technology Advanced Research discovered that one such hydrous mineral also enters an exotic superionic phase, similar to water ice in giant planets. The results are published in