Spring 2025 G&G Available Now
June 5, 2025
A variety of topics awaits you in the Spring issue of G&G. With three feature articles, our regular features, a recap of the 2025 Tucson shows, and the annual G&G Challenge quiz, there’s something for everyone inside.
The 3309 cm–1 Series in Sapphire and Ruby: A Focus on FTIR Peak Position Variation
Drs. Wasura Soonthorntantikul and Aaron Palke share their study of the 3309 cm–1 series in corundum, providing criteria for accurately identifying three hydrogen-related peaks in the infrared spectra of certain types of ruby and sapphire. Detection of this series can be indicative of heat treatment.
A Study of the Winston Red: The Smithsonian’s New Fancy Red Diamond
A group of GIA and Smithsonian researchers, led by Dr. Gabriela Farfan, present the first scientific and historical study of the 2.33 ct Winston Red diamond, exploring its cause of color and geographic origin. Recently added to the Smithsonian’s National Gem Collection, the Winston Red is the fifth-largest known Fancy red diamond in existence.
Emeralds in Catherine de’ Medici’s Pendant: An Unexpected Geographic Origin
Dr. Gérard Panczer and fellow colleagues use archival research and gemological characterization to identify the geographic origin of two emeralds set in a pendant linked to Catherine de’ Medici, Queen of France from 1547 to 1559. The emeralds’ Pakistani origin provides strong evidence of trade routes between Asia and Europe during the sixteenth century or earlier.
Lab Notes
GIA’s global laboratory staff present their latest findings in the Lab Notes section, including a report on CVD-grown gem diamonds from Plasmability, a black opal with unique play-of-color, and a submission of 35 loose non-nacreous pearls arranged in a necklace layout.
Micro-World
The Micro-World section, dedicated to the inner world of gemstones, features native copper inclusions in two chalcedony quartz cabochons, aragonite snowflake inclusions in opal, prismatic elongated zircon in Kashmir sapphire, and more.
Gem News International
The Gem News International section presents our coverage of the 2025 Tucson gem shows, compiling interesting finds, handcrafted designs, popular trends, and more, including gemstone artisan keycaps, a spectacular specimen of “rainbow calcite,” and unique bangle designs.
Gems & Gemology Challenge
The spring issue also offers the 2025 Gems & Gemology Challenge quiz. Score 75% or better and you’ll receive a certificate of completion; earn a perfect score and your name will be listed in the Fall 2025 issue. Entries for the Challenge must be submitted online by September 1, 2025.
Erica Zaidman is associate editor of Gems & Gemology at GIA in Carlsbad, California.
