Dr. Tobias Häger

Tobias Häger studied mineralogy at the Johannes Gutenberg-University Mainz (Germany) and wrote his diploma thesis on “Heat Treatment of Corundum”. Parallel to his studies, he worked in the Centre for Gemstone Research at the University of Mainz. After his PhD on the topic “Interaction of Trace Elements in Corundum,” he worked as a scientific assistant at the University of Mainz in 1998.


He supervised several national and international projects e.g. in Madagascar, Zambia, Sri Lanka, Thailand and Vietnam. Additionally, Tobias Häger also gives lectures in Mainz and at the University for Applied Sciences in Idar-Oberstein. Since 2010, he is managing the Centre for Gemstone Research at the Johannes Gutenberg-University and the Institute for Gemstone Research in Idar-Oberstein.

Colombian Emeralds - an update


In 2018, a team of geoscientists from the university de los Andes (Bogota; Colombia) and from the Johannes Gutenberg-University of Mainz (Germany) visited the two emerald belts (Chivor area and Muzo area) in Colombia twice. During these two field trips, several emeralds and the host material from small and large scale mines were collected. The emeralds were characterized by advanced gemmological methods. Electron microprobe analysis was used to determine the major elements except beryllium. Trace elements and beryllium were measured by laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS). To analyze the beryllium content, a special beryllium standard was developed. UV-Vis-NIR- and Raman-spectrometry were used to determine the causes of colour and ratios of water type 1 and 2 in the channel side. These results will be compared and discussed with the literature.

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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