J. Theo Kloprogge, MSc in Geology, PhD in Geology/Chemistry, is currently Adjunct Professor at the Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, Philippines. From 2014 till the end of 2024, he was an Honorary Senior Fellow at the School of Earth and Environmental Sciences, University of Queensland, Australia. He has been teaching analytical chemistry, inorganic chemistry and mineralogy/crystallography for many years. During the past 30+ years Dr. Kloprogge has been working as a mineralogist (in particular clay mineralogy) and spectroscopist. The results of this work have been published in nearly 300 papers in international peer reviewed journals as well as in a number of book chapters (including Dev. Clay Sci. Vol. 7), 6 books (as author and/or editor, including Dev. Clay Sci. Vol. 8) and 1 patent.