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Gems & Gemology

A Quantitative Description of the Causes of Color in Corundum

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August Birthstone

Peridot: A Gem with Extraterrestrial Origins

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AI to Revolutionize Diamond Clarity Grading

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featured

Research & News

GIA’s Knowledge Sessions: A N
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:
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
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
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
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
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
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
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
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
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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Gems & Gemology

This Month's

Featured Gems

Featured Gem Peridot
Peridot

Found in lava, meteorites, and deep in the earth’s mantle, yellow-green peridot is the extreme gem.

Fancy Color Diamond
Fancy Color Diamond

Dazzling brilliance. Captivating color. These are the planet’s most valued gems.

Diamond
Diamond

Diamonds are among nature’s most precious and beautiful creations.

Emerald Bluish Green Stone
Emerald

Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine.

Featured Gem Citrine
Citrine

Citrine is the transparent, pale yellow to brownish orange variety of quartz.

View the Gem Encyclopedia

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