Summer 2025 G&G Publication Information
Editorial Staff
| Editor-in-Chief Duncan Pay |
Editors, Gem News Gagan Choudhary Guanghai Shi |
Senior Technical Editor Jennifer Stone-Sundberg |
| Editorial Manager Brooke Goedert |
Editors, Colored Stones Unearthed Aaron C. Palke James E. Shigley |
Technical Editor Tao Z. Hsu |
| Associate Editor Erica Zaidman |
Editor, Diamond Reflections Evan M. Smith |
Assistant Editor Erin Hogarth |
| Editors, Lab Notes Thomas M. Moses Shane F. McClure Sally Eaton-Magaña Artitaya Homkrajae |
Contributing Editors James E. Shigley Raquel Alonso-Perez |
Customer Service (760) 603-4200 gandg@gia.edu |
| Editors, Micro-World Tyler Smith John I. Koivula Nathan Renfro |
Editor-in-Chief Emerita Alice S. Keller |
Production Staff
| Supervisor, Multimedia Design Michael Creighton |
Photo/Video Producer Kevin Schumacher |
Video Production Albert Salvato |
Editorial Review Board
| Ahmadjan Abduriyim Tokyo, Japan |
Peter Heaney University Park, Pennsylvania |
Nathan Renfro Carlsbad, California |
| Timothy Adams San Diego, California |
Richard W. Hughes Bangkok, Thailand |
George R. Rossman Pasadena, California |
| James E. Butler Washington, DC |
Jaroslav Hyršl Prague, Czech Republic |
Sudarat Saeseaw Bangkok, Thailand |
| Alan T. Collins London, UK |
Dorrit Jacob Canberra, Australia |
Karl Schmetzer Petershausen, Germany |
| Aurélien Delaunay Paris, France |
A.J.A. (Bram) Janse Perth, Australia |
Andy Shen Wuhan, China |
| Dona Dirlam Carlsbad, California |
Mary L. Johnson San Diego, California |
Guanghai Shi Beijing, China |
| Sally Eaton-Magaña Carlsbad, California |
Robert E. Kane Helena, Montana |
Elisabeth Strack Hamburg, Germany |
| John L. Emmett Brush Prairie, Washington |
Stefanos Karampelas Thessaloniki, Greece |
Nicholas Sturman Bangkok, Thailand |
| Emmanuel Fritsch Nantes, France |
Lore Kiefert Lucerne, Switzerland |
Tim Thomas Portland, Oregon |
| Eloïse Gaillou Paris, France |
Simon Lawson Maidenhead, UK |
D. Brian Thompson Florence, Alabama |
| Al Gilbertson Carlsbad, California |
Ren Lu Wuhan, China |
Fanus Viljoen Johannesburg, South Africa |
| Gaston Giuliani Nancy, France |
Thomas M. Moses New York, New York |
Wuyi Wang New York, New York |
| Lee A. Groat Vancouver, Canada |
Laura Otter Canberra, Australia |
Christopher M. Welbourn Reading, UK |
| Yunbin Guan Pasadena, California |
Aaron C. Palke Carlsbad, California |
Chunhui Zhou New York, New York |
| George Harlow New York, New York |
Ilene Reinitz Chicago, Illinois |
J.C. (Hanco) Zwaan Leiden, The Netherlands |
About the Cover
This issue’s feature article reviews special optical effects in gemstones, including iridescence, which is displayed in the 7 x 5.7 mm iris agate slice on the cover. The rainbow color is caused by the interference of light as it passes through the fine banding in the agate. Photo by Kevin Schumacher; gift of the Hauser family, in memory of Joel and Barbara Hauser. On the back cover, another optical effect, chatoyancy, results from structural planes in a cat’s-eye zircon from Sri Lanka. Photomicrograph by Nathan Renfro; field of view 1.44 mm.
Printing is by L+L Printers, Carlsbad, CA.
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© 2025 Gemological Institute of America
All rights reserved.
ISSN 0016-626X
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Database Coverage
Gems & Gemology’ s impact factor is 2.6, according to the 2024 Journal Citation Reports by Clarivate Analytics (issued June 2025). G&G is abstracted in Thomson Reuters products (Current Contents: Physical, Chemical & Earth Sciences and Science Citation Index—Expanded, including the Web of Knowledge) and other databases:
| Academic Search Complete (EBSCO) | ProQuest/Cambridge Scientific Abstracts/CSA Illumina | AESIS (Australian Earth Sciences Information System) |
| Current Contents | Referativnyi Zhurnal | Applied Science & Technology Full Text/Abstracts/Index |
| GeoArchive | Russian Academy of Sciences Bibliographies | Biography Index |
| Book Review Digest Plus | GeoRef | British Library Document Supply Centre (BLDSC) |
| TOC Premier (Table of Contents) | Chemical Abstracts | Web of Science |
| CISTI (Canada Institute for Scientific and Technical Information) | Mineralogical Abstracts | Wilson Omni File: Full Text Mega Edition |
| Computers & Applied Sciences Complete | PASCAL (INIST) | Wilson Omni File: Full Text Select |
Manuscript Submissions
Gems & Gemology, a peer-reviewed journal, welcomes the submission of articles on all aspects of the field. Please see the Author Guidelines at www.gia.edu/gems-gemology-author-guidelines or contact the editors (gandgeditorial@gia.edu). Letters on articles published in G&G are also welcome. Please note that Field Reports, Lab Notes, Gem News International, Micro-World, Colored Stones Unearthed, Diamond Reflections, Charts, and In the Spotlight are not peer-reviewed sections but do undergo technical and editorial review.
Copyright and Reprint Permission
Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limits of U.S. copyright law for private use of patrons. Instructors are permitted to reproduce isolated articles and photographs/images owned by G&G for noncommercial classroom use without fee. Use of photographs/images under copyright by external parties is prohibited without the express permission of the photographer or owner of the image, as listed in the credits. For other copying, reprint, or republication permission, please contact the editors (gandgeditorial@gia.edu).
Gems & Gemology is published quarterly by the Gemological Institute of America, a nonprofit educational organization for the gem and jewelry industry.
Any opinions expressed in signed articles are understood to be opinions of the authors and not of the publisher.
