GIA’s Knowledge Sessions: A N
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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The Stories Behind the Photos:
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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Spring 2020 G&G Available N
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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G&G Announces Most Valuable
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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What Country Do My Diamonds and
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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New Technologies and Techniques
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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Diamond Identification
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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Gem Localities and Formation
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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General Gemology and Jewelry
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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Gem Characterization
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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