The quarterly journal of the gemological institute of america

In This Issue
- Gemstones in the Era of the Taj Mahal and the Mughals
- Natural-Color Fancy White and Fancy Black Diamonds
- Unique Vanadium-Rich Emerald from Malipo, China
- Inclusions in Ruby and Sapphire from Thailand
- Hydrothermally Treated Beeswax Amber
- Growth and Color of Cultured Half-Pearls from Phuket
- Hydrogen-Rich Green Diamond Color-Treated by Multi-Step Processing
- New Rhodochrosite Imitation
EDITORIAL
Gem Art of the Taj Mahal, Fancy White and Black Diamonds, and Unique Inclusions in Thai Corundum
Duncan Pay, Editor-in-Chief
An overview of the Fall 2019 Gems & Gemology content.
Articles (8)
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Gemstones in the Era of the Taj Mahal and the Mughals
A look at the gem ornamentation of this landmark, as well as the jewels of the Mughal dynasty.

Natural-Color Fancy White and Fancy Black Diamonds: Where Color and Clarity Converge
A systematic study of the properties of approximately 500 Fancy white and 1,200 Fancy black diamonds.

Unique Vanadium-Rich Emerald from Malipo, China
Spectroscopic and chemical analyses of emeralds from this Chinese deposit show a unique composition.

Mineral Inclusions in Ruby and Sapphire from the Bo Welu Gem Deposit in Chanthaburi, Thailand
Identifies mineral inclusions in corundum from this locality for comparison with other global deposits.

Characteristics of Hydrothermally Treated Beeswax Amber
Reveals the process for hydrothermal enhancement of amber and the means of detection.

Effects of Mollusk Size on Growth and Color of Cultured Half-Pearls from Phuket, Thailand
Determines methods for maximizing production and quality of cultured half-pearls.

Hydrogen-Rich Green Diamond Color-Treated by Multi-Step Processing
Characterization of an intense yellowish green faceted diamond revealed a complex treatment process.

Pressed Gibbsite and Calcite as a Rhodochrosite Imitation
Examines a new rhodochrosite simulant composed of pressed gibbsite and calcite powder.
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MOST VALUABLE ARTICLE AWARD

The Color Origin of Gem Diaspore: Correlation to Corundum
Che Shen and Ren Lu

Gemological Characteristics of Sapphires from Yogo Gulch, Montana
Nathan D. Renfro, Aaron C. Palke, and Richard B. Berg

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
















































































































































































































































































































































































