NEWS & ARTICLES

Robert Weldon talked about this photo during the Behind the Scenes: Untold Stories from GIA Field Gemology Expeditions webinar. The photograph shows a model of Campbell Bridges famous tree-house glowin...
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NEWS & ARTICLES

The tools of a traveling field photographer include a map, notebook, pen, mobile phone with compass app and a digital camera. Photo by Robert Weldon Robert Weldon has traveled the world in pursuit of t...
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NEWS & ARTICLES

After being delayed by the global pandemic, the Spring 2020 edition of Gems Gemology is available now. This issue features two articles that quantitatively analyze the causes of color in corundum and b...
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NEWS & ARTICLES

A matched pair of Kashmir sapphires, approximately 7 carats total. Photo by Robert Weldon/GIA. Courtesy of Amba Gem Corporation Gems Gemology is pleased to announce the winners of the Dr. Edward J. Gbe...
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NEWS & ARTICLES

Dr. James Shigley, GIA Distinguished Research Fellow, giving a lecture for students and the public on Gemstone Country of Origin Reporting March 2020 at GIA in Carlsbad. Photo by Emily Lane/GIA Since 1...
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GIA RESEARCH

Figure 1. Single-crystal CVD diamond. Courtesy of Element Six. SYNTHETIC CVD DIAMOND30 YEARS ON Daniel J. Twitchen Element Six, Global Innovation Centre, Harwell, Oxford, United Kingdom Element Six fir...
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GIA RESEARCH

Figure 1. The canary yellow diamonds from this study showed much lower concentrations of isolated nitrogen than regular type Ib yellow diamonds, which usually show brownish and greenish hues linked to ...
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GIA RESEARCH

Figure 1. Cobalt-blue gem spinel from Baffin Island, Nunavut, Canada. Photo by Lee Groat. SCIENTIFIC STUDY OF COLORED GEM DEPOSITS AND MODERN FINGERPRINTING METHODS Lee Groat University of British Colu...
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GIA RESEARCH

GEMSTONES AND SUSTAINABLE LIVELIHOODS: FROM MINES TO MARKETS Saleem H. Ali Gemstones and Sustainable Development Knowledge Hub, University of Delaware, Newark Colored gemstone supply chains are highly ...
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GIA RESEARCH

Figure 1. Measuring about 7 cm across, this 404.2 ct rough from Angolas Lulo mine is a good example of the irregular shape and surface texture associated with CLIPPIR diamonds. The unusual characterist...
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