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Recently submitted 3.52 ct. CVD-grown diamond.
Five CVD Synthetic Diamonds Greater Than Three Carats

The GIA lab examines five gem-quality CVD-grown diamonds in sizes that reflect the improving technology of the synthetic gemstone industry.

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Blue Sapphires
Article
An In-Depth Gemological Study of Blue Sapphires from the Baw Mar Mine (Mogok, Myanmar)

GIA field gemologists visited Baw Mar operations in 2013, 2014, and 2015. In this study, we analyzed samples collected during two separate expeditions.

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Article
The Magic of Colored Diamonds

Colored diamonds are in the spotlight. They’re routinely breaking records at auction houses. Learn more about these gemological marvels of the rarest order.

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Article
Man-made Diamonds: Questions and Answers

What exactly are man-made diamonds? Find out how they compare to natural diamonds and what you should know.

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Micro-Features of Ruby
Inclusions in Natural, Synthetic, and Treated Ruby

Provides a visual guide to the internal features of natural, synthetic, and treated rubies.

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Synthetic Ruby Overgrowth on Natural Corundum
Article
Analysis of Synthetic Ruby Overgrowth on Corundum

Analysis of synthetic ruby overgrowth on corundum, using analysis of inclusions, UV-Vis-NIR and EDXRF spectroscopy, and LA-ICP-MS.

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Drilled natural pearls examined in this study.
Saltwater Pearls from the Pre- to Early Columbian Era: A Gemological and Radiocarbon Dating Study

Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.

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A blue synthetic star sapphire from past production of Wiede’s Carbidwerk
Synthetic Star Sapphires and Rubies Produced by Wiede’s Carbidwerk, Freyung, Germany

Details the process used by Wiede’s Carbidwerk to produce star synthetic corundum from the mid-1950s through the 1970s.

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On the left is a 5.26 ct Fancy deep blue heart shape HPHT synthetic diamond. On the right is a 5.27 ct Fancy deep blue emerald cut HPHT synthetic diamonds.
Article
The Latest on Synthetic Diamonds

Dr. James Shigley, GIA distinguished research fellow, is one of the foremost experts in diamonds and their identification. In this presentation recorded at the 2017 JCK Las Vegas show, he shares the latest developments about HPHT and CVD synthetic diamond

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CVD overgrowth on natural diamond
A Synthetic Diamond Overgrowth on a Natural Diamond

Analysis of a diamond graded Fancy blue revealed a CVD synthetic overgrowth on natural diamond.

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