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Fluorescence Produced by Optical Defects in Diamond: Measurement, Characterization, and Challenges

How variations in UV lamp output can affect observed fluorescence color and intensity.

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Rainbow hematite from Brazil’s Andrade mine.
Iridescence in Metamorphic “Rainbow” Hematite

Analyzes the substructures that cause the intense iridescence observed in “rainbow” hematite from Minas Gerais, Brazil.

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Three cultured pearls, one natural
Real-Time Microradiography of Pearls: A Comparison Between Detectors

Compares the image quality provided by real-time microradiographic imaging (RTX) units fitted with two different detectors: an image intensifier (II) and a flat panel detector (FPD).

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Emerald crystals from Colombia, Afghanistan, and Zambia
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan, and Zambia

Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.

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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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Irradiated 1.06 ct brownish orange HPHT synthetic diamond
Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond

Demonstrates the importance of this method in identifying diamond treatments, based on the analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.

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Seeking the Legacy of Australian Sapphire
Article
Seeking the Legacy of Australian Sapphire

Australia has been a prolific supplier of blue sapphire and has made enormous contributions to the global sapphire industry that still shape it today.

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A high-tech digitizing machine cradles the books for scanning instead of forcing them into a flat, spine-damaging position.
Article
Rare Books Project Puts Gem and Jewelry History Within Reach

More than 200 historically significant books housed in the GIA Library have been digitized and made available for free.

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Near-colorless and Fancy Vivid purplish pink CVD synthetic diamonds
Observations on CVD-Grown Synthetic Diamonds: A Review

Explores statistical data and defining characteristics of gem-quality CVD synthetic diamonds examined by GIA since 2003.

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Green Amber
Characterization of “Green Amber” With Infrared and Nuclear Magnetic Resonance Spectroscopy

A peridot-like bright greenish yellow to green gem material called “green amber” has recently appeared in the gem market.

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