About the Author: Michel Rautureau began working in 1958 at the French National Centre for Scientific Research's "laboratoire de synthèse atomique et d'optique protonique" a facility dedicated to electron microscopy of clay minerals and cell biology. He worked under the direction of Professor Claude Magnan, author of the famous "Traité de microscopie électronique". Dr. Rautureau received his PhD in 1972; his theses work on the crystalline structure of sepiolite, a fibrous clay mineral, and was soon recognized as an authority on clay minerals. He, with Simonne Caillère and Stéphane Hénin authored "Minéralogie des argiles" a major reference in the subject of the mineralogy of clay minerals and the first book to present their global classification. Dr. Rautureau is a member of Groupe Français des argiles (GFA), Association Internationale Pour L' Étude des Argiles (AIPEA), French society of electron microscopy, French society of Mineralogy, French society of geology, Sociéte botanique de France, Association Française pour l'avancement des Sciences (AFAS), and a member of the administrative council for Section Française de l'Institut International de la Conservation (SFIIC).
M. Celso de Sousa Figueiredo Gomes, is Professor Cathedratico at Univ. d'Aveiro, Portugal. He was Assistant Professor (1961-1967) at the Mineralogical and Geological Museum of the University of Coimbra, Crystallography, Mineralogy, Petrology, and Geology, and was Chief-Geologist of the Geological Survey of Angola from 1968-1974. In 1964 he began his study of Soil and Clay Sciences at the Instituto de Edafologia e Agrobiologia Vegetal of the Consejo Superior de Investigaciones Científica (Madrid), and continued in Aberdeen, Scotland, at the Macaulay Institute for Soil Research. In 1979 he received a PhD in Materials Science from the Leeds University, United Kingdom. He is the author or co-author of over 500 scientific papers and he has organized various National and International Conferences. Dr. Gomes was the founder in (1995) and the co-ordinator (1995 - 2004), of the Portuguese Research Centre for Industrial Minerals and Clays, financed by the Foundation for Science and Technology of the Ministry of Science, Technology and Higher Education, and is presently a member of this Research Centre. Since 1998 he is member of the Editorial Board of Clay Minerals - Journal of the Fine Particle Science. Dr. Gomes is a member of AIPEA (Association Internationale Pour L' Étude des Argiles), the Mineralogical Society (United Kingdom), Clays and Clay Minerals Society (United States of America), Sociedad Española de Arcillas (Spain), Clay Science Society (Japan) and Sociedade Portuguesa de Hidrologia Médica. In 1995 he founded APA (Associação Portuguesa de Argilas), an affiliate of ECGA (European Clay Groups Association) and AIPEA.
Nicole Liewig holds a PhD in geology and is presently Chargée de Recherche at CNRS, Centre Hubert Curien, Strasbourg. Dr. Liewig is a member of GFA, AIPEA, and is research instructor with the International Master of Clay Sciences program in Poitiers France.