A mix of gemmological topics are experienced by gem labs and this presentation will cover some of these. New gemstones from Africa (especially Ethiopia, Mozambique and Madagascar), the origin of Paraiba (Copper-Bearing) tourmalines, low temperature treatments of ruby from Mozambique, clarity enhancements of ruby, sapphire, tourmaline and other gems, reversible color modifications of zircon, and unusual imitations. Stefan Müller studied Geosciences at the Johannes Gutenberg Universität Mainz. His special interest is origin determination of various coloured gemstones working with LA-ICP-MS, EDXRF, EPMA, UV-Vis-NIR, IR and studying inclusions with Raman microscopy. Since 2016 he has worked for the DSEF German Gem Lab and is currently undertaking a PhD about HPHT treatment of natural and synthetic diamonds.

Engelstalige bijeenkomst.