The quarterly journal of the gemological institute of america

IN THIS ISSUE
- Measurement and Characterization of the Effects of Blue Fluorescence on Diamond Appearance
- Detection of Color Treatment and Optical Brightening in Chinese Freshwater “Edison” Pearls
- Pearl Classification: The GIA 7 Pearl Value Factors
- Namak Mandi: A Pioneering Gemstone Market in Pakistan
EDITORIAL
Effects of Blue Fluorescence on Diamond Appearance, Color Treatment and Brightening of “Edison” Pearls, and a Pioneering Gemstone Market in Pakistan
Duncan Pay, Editor-in-Chief
An overview of the Summer 2021 Gems & Gemology content.
Articles (4)

Namak Mandi: A Pioneering Gemstone Market in Pakistan
Documents Namak Mandi’s transformation from a salt market to one of Pakistan’s primary gem trading centers, with a look at the commercial activities taking place today.

Detection of Color Treatment and Optical Brightening in Chinese Freshwater “Edison” Pearls
Analyzes a group of 23 freshwater “Edison” pearls (a trade name referring to near-round freshwater cultured pearls, usually shell bead cultured) using various gemological and advanced instrumental techniques.

Pearl Classification: The GIA 7 Pearl Value Factors
Provides a visual guide to GIA’s approach to classifying and describing pearls.

Measurement and Characterization of the Effects of Blue Fluorescence on Diamond Appearance
Using customized, image-based measurement systems to quantify the effect of fluorescence on the color, brightness, and transparency of gem diamonds viewed in both face-up and table-down orientations.
Regular Features



GEM NEWS INTERNATIONAL
Global coverage of gem sources, notable new gem materials, and recent industry developments.
THE DR. EDWARD J. GÜBELIN
Most Valuable Article Awards

A Quantitative Description of the Causes of Color in Corundum
Emily V. Dubinsky, Jennifer Stone-Sundberg, and John L. Emmett

History of the Chivor Emerald Mine, Part I (1880–1925): From Rediscovery to Early Production
Karl Schmetzer, Gérard Martayan, and Jose Guillermo Ortiz

Naturally Colored Yellow and Orange Gem Diamonds: The Nitrogen Factor
Christopher M. Breeding, Sally Eaton-Magaña, and James E. Shigley













































































































































































































































































































































































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