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the quarterly journal of the gemological institute of america
In This Issue
Natural-Color Blue, Gray, and Violet Diamonds
Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions
An Early Byzantine Engraved Garnet from India: Evidence of Trade Along the Ancient Maritime Silk Road
Cultured Pearls from Lake Kasumigaura: Production and Gemological Characteristics
Sapphires from Yogo Gulch, Montana
Chart: Features of Synthetic Diamonds
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the quarterly journal of the gemological institute of america
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Summer Reading: Diamond Research, Yogo Sapphire, and Byzantine Garnet
Duncan Pay, Editor-in-Chief
An overview of the Summer 2018 Gems & Gemology content.
Articles (6)
![Identification](https://www.gia.edu/images/SU18-Magana-Blue-Diamonds-Fig1A-D-232512-216px.jpg)
Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.
Read More![Color](https://www.gia.edu/images/SU18-Smit-Black-Diamonds-Fig3-callouts-232554-216px.jpg)
Black Diamonds from Marange (Zimbabwe): A Result of Natural Irradiation and Graphite Inclusions
Characterizes a suite of 40 natural brown to black diamonds from this deposit so that they can be distinguished from suspected treated black diamonds.
Read MoreAn Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road
Analyzes the chemical composition and inclusion characteristics of this ancient artifact.
Read More![Localities](https://www.gia.edu/images/SU18-Abduriyim-Fig3-LR-232341-216px.jpg)
Cultured Pearls from Lake Kasumigaura: Production and Gemological Characteristics
Examines Japanese “Kasumiga” freshwater cultured pearls, which grow in a variety of colors.
Read More![Localities](https://www.gia.edu/images/SU18-Renfro-Fig1-232477-216px.jpg)
Gemological Characterization of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Read More![Synthetics](https://www.gia.edu/images/SU18-synthetic-diamond-chart-callouts-232524-216px.jpg)
Features of Synthetic Diamonds
Presents a visual guide to the growth processes and major gemological spectroscopic features of synthetic diamonds.
Read MoreRegular Features
![Lab Notes](https://www.gia.edu/images/lab-notes-landing-page-300x169.jpg)
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![Gem News](https://www.gia.edu/images/gni-landing-page-300x169.jpg)
Gem News International
Global coverage of gem sources, notable new gem materials, and recent industry developments.
View All (13)![Diamonds from the Deep](https://www.gia.edu/images/Diamonds-from-the-deep-crystals-web-thumb-221670-216px.jpg)
Diamonds From the Deep
Explores the role of diamonds in our understanding of the natural world.
View All (1)![Book Review](https://www.gia.edu/images/147796_book.jpg)
MOST VALUABLE ARTICLE AWARD
![Most Valuable Article 1st Place Tao Hsu](https://www.gia.edu/images/1st-MVA-Tao-Hsu-130x130.png)
Big Sky Country Sapphire: Visiting Montana’s Alluvial Deposits
Tao Hsu, Andrew Lucas, Robert E. Kane, Shane F. McClure, and Nathan D. Renfro
![Most Valuable Article 2nd Place Darwin Fortaleche](https://www.gia.edu/images/2nd-MVA-Darwin-Fortaleche-130x130.png)
Colombian Emerald Industry: Winds of Change
Darwin Fortaleché, Andrew Lucas, Jonathan Muyal, Tao Hsu, and Pedro Padua
![Most Valuable Article 3rd Place Xiaoyan Feng](https://www.gia.edu/images/3rd-MVA-Xiaoyan-Feng-130x130.png)
Characterization of Mg and Fe Contents in Nephrite Using Raman Spectroscopy
Xiaoyan Feng, Yong Zhang, Taijin Lu, and Hui Zhang
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