The quarterly journal of the gemological institute of america

In This Issue
- A Quantitative Description of the Causes of Color in Corundum
- The Evolution of Chinese Jade Carving Craftsmanship
- Color Characteristics of Blue to Yellow Beryl from Multiple Origins
- History of the Chivor Emerald Mine, Part I (1880–1925): From Rediscovery to Early Production
- Rhodonite-Pyroxmangite from Tanatz Alp, Switzerland
EDITORIAL
Dive Into Spring: Investigations into Corundum and Beryl Color, Jade Artistry, the Chivor Emerald Mine’s History, and Swiss Rhodonite…
Duncan Pay, Editor-in-Chief
An overview of the Spring 2020 Gems & Gemology content.
Articles (5)

A Quantitative Description of the Causes of Color in Corundum
Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.

Brazilian Diamonds: A Historical and Recent Perspective
Recounts the history, geology, and notable localities of diamond mining in Brazil, and outlines plans for future diamond production.

Color Characteristics of Blue to Yellow Beryl from Multiple Origins
Discusses the features of alkali elements and their influence on the color of blue to yellow beryl.

History of the Chivor Emerald Mine, Part I (1880–1925): From Rediscovery to Early Production
Chronicles developments at the Chivor emerald mine in Colombia between 1880 and 1925, based on archival records.

Rhodonite-Pyroxmangite from Tanatz Alp, Switzerland
Investigates the chemical, physical, and gemological properties of attractive rhodonite-rich rocks from this Swiss deposit.
Regular Features


Diamonds From the Deep
Explores the role of diamonds in our understanding of the natural world.

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

Geographic Origin Determination of Blue Sapphire
Aaron Palke, Sudarat Saeseaw, Nathan Renfro, Ziyin Sun, and Shane McClure

Decade of Ruby from Mozambique: A Review
Wim Vertriest and Sudarat Saeseaw

Gemstones in the Era of the Taj Mahal and the Mughals
Dona Mary Dirlam, Chris L. Rogers, and Robert Weldon
















































































































































































































































































































































































