Blog der Deutschen Gemmologischen Gesellschaft

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Herausgeber: 
Deutsche Gemmologische Gesellschaft e.V.
Prof.-Schlossmacher-Str. 1
D-55743 Idar-Oberstein

 

Copyright:
Für alle Beiträge behält sich die Deutsche Gemmologische Gesellschaft (Deutsche Gesellschaft für Edelsteinkunde) e.V. sämtliche Rechte vor, insbesondere die des Nachdrucks, der Übersetzung in andere Sprachen und der photomechanischen Wiedergabe. Die veröffentlichten Beiträge stellen – soweit namentlich bezeichnet – die Auffassung der Autoren dar und geben nicht notwendig die Meinung von Herausgeber und Schriftleitung wieder. (Content of this journal may not be reproduced in any form without the permission of the German Gemmological Association. Opinions expressed do not necessarily reflect the views of the Association.)

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Current Posts


Tanzanite

Tanzanite is often called the "stone of the 20th century", as it was discovered in 1967 and became the first popular natural "substitute" for the blue colour of sapphire. Gübelin...

Spinel

The name spinel can be traced back to the 16th century. It was mentioned for the first time in 1533 by C. Leonardi, and Georg Agricola (1494-1555) wrote in "De Natura Fossilium":...

Stabilised Aquamarine Cabochon with Unusual Colouring

Recently, the authors examined a 17.20 et greenish blue oval cabochon that exhibited a noticeably blurry, uneven colour distribution (Figure 18). lt had a spot RI of 1.57, as...

Yellow sapphire with unstable colour centre

Fig. 1: Yellow sapphire of 4.57 ct with a unstable colour. (A) shows the stone as it was submitted for examination, (B) after a fading test under a strong lamp for 15 min, (C)...

Comparison of Emeralds from the Chitral District, Pakistan, with other Pakistani and Afghan Emeralds

Emeralds from various deposits in Pakistan (Chitral, Swat and Khaltaro) and Afghanistan (Panjshir and Laghman) were examined and compared. In addition, we compared the...

Opal from Honduras

Occurrences of opal in the Central American country Honduras are already known since the mid-19th century. Opals with and without playof-colour are found in volcanic rocks,...

Padparadscha

Padparadscha is undoubtedly one of the rarest gemstones. The corundum variety, whose most important deposits are the gemstone placers of the island of Sri Lanka (Ceylon),...

Emerald

The use of emeralds for jewellery dates to Egyptian times, when greenish crystals found in the Gebel Sikait area were known as early as 3500 BC. The pits in the area later became...

Violet-pink coloured garnet with blue apatite inclusions

Purple-pink coloured garnets with blue apatite inclusions have been on the market for some time and are becoming increasingly popular. The garnets come from a location in...

National and International Cooperation of DGemG and DSEF

One of the most important reasons for the almost simultaneous founding of the first gemmological associations in the 1930s (Gemmological Association of Great Britain and...

Idar-Oberstein, the gemstone trade and gemstone research

Unlike other industry sectors which come to a standstill as local rough material production becomes scarce, the gemstone industry in Idar-Oberstein endures, 150 years after the...

Moldavite from Chlum, Czech Republic: Mining and Gem Properties

One of the most well known and popular natural glasses is moldavite, which formed during a meteorite impact about 14.8 million years ago. Today, moldavite is mainly obtained from...

Spectroscopic Investigation of Colour and Colour Modification as a Major Topic of Gemstone Research at the DGemG and DSEF

As long as people have adorned themselves with gemstones, they have also tried to enhance the beauty of these natural products. Treatment options have been used for centuries to...

On the Colour Mechanism of Blue Gahnite from Nigeria

Gem-quality blue gahnite from Jemaa in central Nigeria has gemmological properties (RI and SG) and a chemical composition indicating relatively pure gahnite (90.7–91.3%). The...

24th FEEG-Symposium in Barcelona, Spain

On the 13th of January 2024, the "Escola de Gemmologica" of the Faculty of Earth Sciences at the University of Barcelona hosted the 24th symposium of the "Federation for European...

Special seminar "Scientific methods in gemmology"

You want to extend your knowledge in gemmology? You are looking for practical and feasible ways to add advanced methods to your gemmological laboratory? Due to the steady...

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