Research Interests: Mineralogy-Crystallography, Anisotropy-Texture Development, Field Investigations. His research is in crystallography, mineralogy, structural geology and rock deformation. Most recently (see research interests and publications), emphasis has been on understanding seismic anisotropy in the earth by investigating the development of preferred orientation under expreme conditions (temperature and pressure) with neutron diffraction, synchrotron x-rays and electron microscopy. The research is funded by NSF and DOE. He wrote an introductory mineralogy book, published by CambridgeUniversity Press. A new edition has appeared in 2016.