_Professor Dr. Daniel R. Neuville, Géomatériaux, CNRS-Institut de physique du globe de Paris, Université de Paris, 1 rue Jussieu, 75005 Paris, France. neuville@ipgp.fr _Professor Dr. Grant S. Henderson, Department of Earth Sciences, University of Toronto, 22 Russell St, Toronto, Ontario, M5S 3B1, Canada. henders@es.utoronto.ca _Professor Dr. Donald B. Dingwell, Department. Earth and Environmental Sciences, Ludwig-Maximilian-University (LMU), Theresienstrasse 41/III, D-80333 Munich, Germany. dingwell@lmu.de