Conclave 2026

Thomas is the Director and co-founder of GGTL Laboratories (GGTL Laboratories Liechtenstein). He has founded Gemlab (Liechtenstein) in 1996 and has joined a very close collaboration with GemTechLab in Geneva in 2011, through which GGTL Laboratories emerged, with the three member labs in Liechtenstein, Geneva and Antwerp (http://www.ggtl-lab.org).

Thomas has been working on the analysis of diamonds, colored stones and pearls for the past 30 years, and is a respected expert in the field of gemological research, with extensive experience in the complex topic of colored diamond. Besides his expertise as a multidisciplinary gemmologist with specialization in diamond research and testing, he has developed and built many analytical instruments for gem and pearl testing in the past years.

He holds a PhD in Physics (materials science) from the University of Nantes, France, a university diploma in advanced gemology from the University of Nantes (DUG diploma), and gemological diplomas by the GIA (GG), by the British Gemological Association (FGA), and by the Swiss Gemological Society (SGG).