1. Centre for Science at Extreme Conditions and School of Geosciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, U.K.
2. Geodynamics Research Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
3. Institut für Mineralogie, Corrensstrasse 24, Universität Münster, 48149 Münster, Germany
4. Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, U.K. j.p.attfield@ed.ac.uk