Editorial
Intriguing Sapphire from Montana, a New Source of Emerald in Central China, and Arkansas Turquoise
Duncan Pay, Editor-in-Chief
An overview of the Winter 2025 Gems & Gemology content.
Articles (3)

The Primary Sapphire Occurrence at French Bar Sill Along the Missouri River, Near Helena, Montana
Reports on a new source of primary gem-quality sapphire from Montana, comparing its inclusions and trace element chemistry with those from secondary sources in the state.

Characterization of Emeralds from Zhen’an County in Shaanxi, China
Presents a comprehensive analysis of the gemological, spectroscopic, and trace element characteristics of a set of Shaanxi emerald samples based on standard and advanced gemological methods.

An Evaluation of Turquoise from the Mona Lisa Mine in Arkansas
Examines samples of Mona Lisa turquoise to identify their chemistry and structure, revealing copper as a major elemental component of the material.
Regular Features



GEM NEWS INTERNATIONAL
Global coverage of gem sources, notable new gem materials, and recent industry developments.

COLORED STONES UNEARTHED
Explores the geological concepts related to colored stone formation.
Special Features

IN THE SPOTLIGHT
A photo tour of the GIA Museum’s latest exhibit featuring extraordinary crystals and gems central to the cultures of southern Asia.
THE DR. EDWARD J. GÜBELIN
Most Valuable Article Awards

Laboratory-Grown Diamonds: An Update on Identification and Products Evaluated at GIA
Sally Eaton-Magaña, Matthew F. Hardman, and Shoko Odake

Observations of Oval-, Pear-, and Marquise-Shaped Diamonds: Implications for Fancy Cut Grading
Ilene M. Reinitz, Al Gilbertson, Troy Blodgett, Amanda Hawkes, James Conant, and Abhijith Prabhu

Chemical Analysis in the Gemological Laboratory: XRF and LA-ICP-MS
Ziyin Sun, Michael Jollands, and Aaron C. Palke

















































































































































































































































































































































































