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Deutsche Gemmologische Gesellschaft eV (German Gemmological Association) DGemG

DGemG Gemstone Library

The constant developments in the field of gemmology due to the discovery of new gem deposits, the occurrence of new syntheses and imitations, and in particular the technological advances in the development of new treatments, require the practical gemmologists to keep their knowledge steadily up-to-date.

The DGemG Gemstone Library is constantly updated, providing members and seminar participants of the German Gemmological Association (DGemG) up-to-date information on the characteristics and diagnostic inclusions of all commercially important gemstones as well as an extensive fund of collector stones.

Members use their five-digit membership number on their current membership card as their username and password.
Seminar participants request the current login data with their lecturer.

Not a member yet? Here is the membership application.

Woud you like to see a sample entry? Click here:
Opal - Characteristics
Opal - Types and Varieties


Editorial board: Dr. rer. nat. Tom Stephan, M.Sc., F.G.G., E.G. (responsible) and Dr. rer. nat. Ulrich Henn, Dipl.-Min., assisted by Qi Wang, M.F.A., F.G.G., E.G.

The German Gemmological Association (DGemG) reserves all rights for all contributions. The contributions are exclusively for private use. Any further use of texts and images for non-private use requires the written permission of the German Gemmological Association (DGemG).