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A face-up view of a cushion cut diamond with blue color.
Article
Gems & Gemology’s 7 Most Unusual Encounters from 2019

Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.

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G&G Brief presents an overview of the content of the Fall 2015 issue of Gems & Gemology.
Article
Autumn 2015 G&G: Trapiche Emeralds, Synthetic Diamonds and a Large Diamond Source

G&G Brief presents an overview of the content of the Autumn 2015 issue of Gems & Gemology.

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Summer G&G 2015
Article
Summer 2015 G&G: Dual-Stars, Photomicrography Guide, Rubies from Tajikistan, New Micro-World Section

G&G Brief presents an overview of the content of the Summer 2015 issue of Gems & Gemology.

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CVD synthetic diamond
CVD Synthetic Diamond with Fancy Vivid Orange Colour

Strong absorptions from N-V centres were the main cause of a CVD synthetic diamond’s pinkish orange bodycolour.

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Irradiated CVD Synthetic Diamond
Heavily Irradiated CVD Synthetic Diamond

A look at the first CVD synthetic diamond examined at GIA that has been irradiated to a blue colour.

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1.50 ct Fancy Dark grey CVD synthetic diamond
Two Fancy Dark Grey CVD Synthetic Diamonds

Examination of two CVD synthetic diamonds with an unusual Fancy Dark grey colour.

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Large synthetic moissanite with silicon carbide polytypes

Examination of the properties of a synthetic moissanite specimen submitted as a black diamond.

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A Large Irradiated Green-Yellow Diamond

GIA's identification of a large diamond as artificially irradiated based on careful spectroscopic analysis and lab database review.

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0.45 ct Pink CVD Labgrown Diamond
Strongly Coloured Pink CVD Lab-Grown Diamonds

Pink CVD lab-grown products can be separated from natural and treated-colour natural pink diamonds by a combination of gemmological and spectroscopic properties, which are explored in this study.

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Coloured Diamonds in the Aurora Butterfly of Peace Collection
The “Type” Classification System of Diamonds and Its Importance in Gemmology

Knowledge of type allows gemmologists to better evaluate if a diamond might be treated or synthetic, and whether it should be sent to a laboratory for testing.

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