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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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Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.

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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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Sapphire Chart Article: Suggested Reading on Sapphires and Their Inclusions

Suggested Reading on Sapphires and their Inclusions

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Fluorescence image of Aurora Butterfly of Peace
An Introduction to Photoluminescence Spectroscopy for Diamond and Its Applications in Gemmology

Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.

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Fluorescence produced by optical defects in diamond: measurement, characterisation and challenges

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

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Evan Smith studies images of diamond inclusions on a computer.
Article
Postdoctoral Programme Gives Scientists Access to Rare Research Opportunities

GIA’s postdoctoral programme gives researchers access to gemmological data, equipment, and rare, unusual and large gems in its laboratories.

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Green Amber
Characterisation 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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Five-strand Natural Pearl Necklace
X-ray Computed Microtomography: Distinguishing Natural Pearls from Beaded and Non-Beaded Cultured Pearls

The distinction of natural from cultured pearls has traditionally been based on X-radiography.

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Spectral Differentiation Between Copper and Iron Colourants in Gem Tourmalines
Spectral Differentiation Between Copper and Iron Colourants in Gem Tourmalines

The authors used Vis-NIR spectral measurements combined with LA-ICP-MS data to investigate the usefulness of absorption spectra.

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