Hans-Rudolf Wenk is Professor of the Graduate School in the Department of Earth and Planetary Science at the University of California, Berkeley. Since joining the Berkeley faculty, he has been engaged in teaching and research, covering a wide field of mineralogy, from feldspars to carbonates, metamorphic rocks to shales, and from the Earth's surface to the inner core. His particular focus has been on microstructures, investigated using electron microscopy and synchrotron X-rays.