2025 AGA Tucson Gemological Conference and Gala

Dr. Emmanuel Fritsch is a professor of physics at the university of Nantes (NantesUniversité) in western France. He holds a geological engineering degree from the ENSG, Nancy, Eastern France, and a Ph.D. from the Sorbonne (university Paris VII) in Paris. He worked for nearly ten years at the Gemological Institute of America (GIA) in the USA, where he became a Graduate Gemologist (GG), and was promoted to manager of GIA Research from 1992 to 1995. His research is currently conducted at the Institut des Matériaux Jean Rouxel (IMN-CNRS) in Nantes.

Dr. Fritsch wide range of interests includes all aspects of science that can be applied to gems. His self-assigned mission is to make gemology more scientific. He has authored over 400 articles and collaborated on over 20 books. He is responsible for the DUG (Diplôme d’Université de Gemmologie) diploma, an internationally recognized advanced gemology program.

Brecken Branstrator is the editor-in-chief of Gemworld International’s GemGuide publication, the industry leader for gemstone pricing, market information, and trends. She has written about gems and jewelry for a decade. She has dedicated herself to covering the colored gemstone sector in depth, from topics like supply and pricing to responsible sourcing developments and other issues of interest. She has traveled extensively across the United States and internationally to attend trade shows and conferences or visit brands and source markets firsthand.

Hanco Zwaan joined the National Museum of Natural History Naturalis (now called Naturalis Biodiversity Center), Leiden, the Netherlands, in 1995, as curator of minerals and gems and became head of the Netherlands Gem Laboratory soon thereafter. Issuing gem and pearl identification reports, diamond grading reports, and teaching gemmology, is part of his daily work, as well as studying processes in the Earth’s crust that have led to the formation of gemstones.

Dr. Zwaan has a PhD from Free University of Amsterdam on Geology, specializing on the formation of emeralds, with the publication ‘the Gemmology, geology and origin of the Sandawana emerald deposits, Zimbabwe’.

Apart from this focus on emeralds, he published articles on a variety of other gemmological and mineralogical topics, among which on copper-bearing tourmaline, sapphire and pearls.

He teaches the Netherlands Gem Laboratory’s education program in association with Gem-A, London (Gemmology Foundation and Gemmology Diploma, leading to the world-wide recognised qualification FGA), and is also involved in education leading to the European Gemmology diploma (FEEG).

Hanco Zwaan is currently president of the World Jewellery Confederation (CIBJO) Gemmological Commission, dealing with nomenclature issues and laboratory best practices. On behalf of this commission he is also co-chairing a committee on gem varietal names, dealing with variety definitions and trade names.

Sharrie Woodring, GIA GG, FGA, is an experienced gemologist with over 25 years in the field. Since 2005, she has served as a Senior Gemologist at the GCAL lab in New York, where her expertise lies in analyzing and grading a wide range of gemstones, with a particular focus on lab-grown and colored diamonds. Her experience includes international assignments like the analysis of the remarkable 1,109-carat Lesedi La Rona diamond for Sotheby’s and Lucara in 2016. Throughout her career, Sharrie has been at the forefront of gemological advancements, from the introduction of the HPHT color treatment process to the progression of lab-grown diamonds.

She has played a key role in developing GCAL’s diamond certification procedures, ensuring accuracy through research instrumentation and adherence to strict ISO standards. Her passion for the field is further reflected in her contributions to gemological education and her authorship of a book on lab-grown diamonds. She is actively engaged in facilitating the global expansion of laboratory services at GCAL and the integration of AI diamond grading instrumentation from Sarine Technologies into their grading processes.

Dr. Michael S. Krzemnicki is director at the Swiss Gemmological Institute SSEF, internationally reputed as leading laboratory for the testing of coloured stones, diamonds and pearls.

Apart from working at the SSEF since more than 25 years, he is lecturer at the University Basel and is supervising gemmology-related research projects in collaboration with Swiss universities and international research facilities. In 2017, he was awarded the Gemmological Excellence Award of the Swiss Gemmological Society.

Furthermore, he is appointed member of the Scientific Board of the Swiss Gemmological Society SGS, the Executive Board of the International Gemmological Conference IGC, the Committee on Gemstone Varietal Names (CVN) by CIBJO, the Laboratory Manual Harmonisation Committee LMHC, the Technical Board for the Standardization of Fei Cui (Jadeite) Testing by HKTDC, and further technical and editorial boards.

As an internationally renowned expert he is a frequent speaker at gemmological conferences worldwide and has published numerous articles in scientific and trade journals on gems, pearls, and new analytical testing methods.