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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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Optical Defects in Diamond: A Quick Reference Chart

A simple chart on optical defects in diamond, including those that produce coloration and fluorescence colors.

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Hydrogen-rich Diamonds
Gray-To-Blue-To-Violet Hydrogen-Rich Diamonds from the Argyle Mine, Australia

The Argyle diamond mine is the only known source of type IaB hydrogen- and nitrogen-rich diamonds colored gray to blue to violet.

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Natural Mixed Cape Diamond
Mixed-Type Cape Diamond

A Fancy orangy yellow “cape” diamond featured an unexpected 480 nm band, a defect normally associated with orange color.

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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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Article
Spring 2015 G&G Examines Blue Spinel, Chinese Jewelry Design and the Latest in Synthetics

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

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Illustration and spectrum showing absorption in yellow diamond
Visible Absorption Spectra of Colored Diamonds

Features a foldout chart containing representative visible spectra and photos of the major color categories of diamond.

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0.76 ct HPHT-treated Diamond
“Fluorescence Cage”: Visual Identification of HPHT-Treated Type I Diamonds

HPHT-treated type I diamonds of various colors may exhibit unusually intense fluorescence at the facet edges and junctions.

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Treated Green Diamonds
Detection of Treatment in Two Unusual Green Diamonds

A pair of sharp absorption bands in the near-infrared region, referred to as H1b and H1c, have been detected in one (and the H1b band in the other) of two green diamonds known to have been treated.

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Treated-Color Pink-To-Red Diamonds from Lucent Diamonds Inc.

Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.

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