Winter 2024 G&G Available Now
February 7, 2025
The Winter 2024 special edition of Gems & Gemology is devoted to advanced gemological testing. A valuable resource for gemologists, the issue is packed with a wealth of applicable content on the analytical techniques used in today’s gemological laboratories.
ANALYTICAL TECHNIQUES IN GEMOLOGY: A HISTORICAL OVERVIEW
In an introduction to the issue, Dr. James Shigley provides a look at the history of gem testing, from the first analytical instruments used at GIA leading to today’s instrumentation, developed to address increasingly complex identification challenges.
APPLICATION OF UV-VIS-NIR SPECTROSCOPY TO GEMOLOGY
Dr. Shiyun Jin and coauthors explore the use of UV-Vis-NIR spectroscopy to measure how gemstones absorb and interact with light, uncovering information about their composition, origin, and potential treatments.
INFRARED SPECTROSCOPY AND ITS USE IN GEMOLOGY
Dr. Christopher M. Breeding and Nicole Ahline cover the applications of infrared spectroscopy in gem testing, demonstrating how FTIR spectra can help separate natural from laboratory-grown gems as well as identify treatments.
SHINING A LIGHT ON GEMSTONE PROPERTIES: AN EXPLORATION OF PHOTOLUMINESCENCE SPECTROSCOPY
A team led by Dr. Sally Eaton-Magaña presents an article on the utilization of photoluminescence spectroscopy to reveal details about gemstone identity and color origin through the detection of microscopic defects and impurities.
RAMAN SPECTROSCOPY AND X-RAY DIFFRACTION: PHASE IDENTIFICATION OF GEM MINERALS AND OTHER SPECIES
Drs. Shiyun Jin and Evan Smith review two advanced analytical tools for phase identification, Raman spectroscopy and X-ray diffraction, which identify the atomic structure of materials.
CHEMICAL ANALYSIS IN THE GEMOLOGICAL LABORATORY: XRF AND LA-ICP-MS
Ziyin Sun and fellow researchers provide a technical overview of the two main chemical analysis techniques used in gemological testing, XRF and LA-ICP-MS, and present several examples of their use in the laboratory.
GLOWING GEMS: FLUORESCENCE AND PHOSPHORESCENCE OF DIAMONDS, COLORED STONES, AND PEARLS
Dr. Ulrika D’Haenens-Johansson and coauthors explore the use of photoluminescence imaging in gemstone characterization, examining the mechanisms and characteristics that create a glow in gemstones, followed by the applications to diamonds, colored stones, and pearls.
APPLICATIONS OF X-RAY RADIOGRAPHY AND X-RAY COMPUTED MICROTOMOGRAPHY IN GEMOLOGY
Drs. Chunhui Zhou and W. Henry Towbin review the crucial role of X-ray radiography and X-ray computed microtomography in pearl identification, offering a brief history of pearl testing, basic instrumental theory, and the methodology for different types of pearls.
METROLOGY AT GIA
David Nelson and Dr. Ilene Reinitz deliver an in-depth look at GIA’s rigorous metrology practices, ensuring accurate gemological measurements across its global laboratories.
ANALYSIS OF GEMSTONES AT GIA LABORATORIES
In the issue finale by Nicole Ahline and Jessa Rizzo, follow a submitted stone’s journey through the GIA lab, from intake to testing and analysis to reporting.
Erica Zaidman is associate editor of Gems & Gemology at GIA in Carlsbad, California.
