Dr. Michael Krzemnicki

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 for 20 years, he is Assistant Professor at the University Basel and is supervising gemmology-related research projects in collaboration with Swiss universities and international research facilities. Furthermore, he is appointed member of the Scientific Board of the Swiss Gemmological Society SGS, the Executive Board of the International Gemmological Conference IGC, and member of the HKTDC Technical Board for the standardization of Fei Cui (Jadeite) testing, and other technical and editorial boards. As an internationally renowned expert he is frequent speaker at gemmological conferences worldwide and has published numerous articles in scientific and trade journals on gems, pearls, and new analytical testing methods.

Where is the boundary between colour varieties of gems?


Minerals of gem-quality come in a wide range of colours. From a lab’s perspective, setting internal standards and protocols to grade the colour of gems and establishing boundaries for gem varieties are of high importance. In this presentation, real borderline cases will be presented, among those ruby/pink sapphire, padparadscha/fancy sapphire, emerald/green beryl, Co-spinel and alexandrite/chrysoberyl.

Impressions from the first EGS 2007 in Idar-Oberstein

Register for the European Gemmological Symposium
on May 24 – 26, 2019 in Idar-Oberstein.

During the two days’ conference, you will enjoy numerous internationally recognized and distinguished speakers, as well as a broad spectrum of subjects including diamonds, coloured stone, pearls and jewellery.

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