The quarterly journal of the gemological institute of america

In This Issue
- Application of UV-Vis-NIR Spectroscopy to Gemology
- Infrared Spectroscopy and Its Use in Gemology
- An Exploration of Photoluminescence Spectroscopy
- Raman Spectroscopy and X-Ray Diffraction
- Chemical Analysis in the Gemological Laboratory
- Fluorescence and Phosphorescence of Diamonds, Colored Stones, and Pearls
- Applications of X-Ray Radiography and X-Ray Computed Microtomography
- Metrology at GIA
INTRODUCTION
Analytical Techniques in Gemology: A Historical Overview
James E. Shigley
A look at the history of analytical instruments used for gem testing.
Articles (9)

Application of UV-Vis-NIR Spectroscopy to Gemology
UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ranges, revealing crucial information about their composition, origin, and potential treatments.

Infrared Spectroscopy and Its Use in Gemology
Infrared spectroscopy, specifically FTIR analysis, measures atomic vibrations to determine identity, cause of color, and potential treatments by analyzing how a gemstone absorbs infrared light.
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Raman Spectroscopy and X-Ray Diffraction: Phase Identification of Gem Minerals and Other Species
Raman spectroscopy and XRD techniques are used to identify gemstone species through their atomic-scale structures, with Raman spectroscopy analyzing inelastic light scattering from crystal lattice vibrations and XRD examining X-ray interference patterns from atomic layers.

Chemical Analysis in the Gemological Laboratory: XRF and LA-ICP-MS
The primary chemical analysis methods applied in gemology are XRF, which uses X-ray emissions for nondestructive testing, and LA-ICP-MS, which provides detailed analysis and greater sensitivity. LA-ICP-MS has become essential for origin determination and treatment detection.

Shining a Light on Gemstone Properties: An Exploration of Photoluminescence Spectroscopy
Photoluminescence spectroscopy examines how gemstones absorb and emit light, uncovering crucial details about their identity and color origin through the detection of microscopic defects and impurities.

Shining a Light on Gemstone Properties: An Exploration of Photoluminescence Spectroscopy
Photoluminescence spectroscopy examines how gemstones absorb and emit light, uncovering crucial details about their identity and color origin through the detection of microscopic defects and impurities.

Analysis of Gemstones at GIA Laboratories
GIA’s laboratories use advanced instrumentation and research to deliver accurate grading, identification, and origin determination for natural and laboratory-grown diamonds, colored stones, and pearls.
THE DR. EDWARD J. GÜBELIN
Most Valuable Article Awards

Yellow Sapphire: Natural, Heat-Treated, Beryllium-Diffused, and Synthetic
John L. Emmett, Ungkhana Atikarnsakul, Jennifer Stone-Sundberg, and Supharart Sangsawong

Gemological Characterization of Montana Sapphire from the Secondary Deposits at Rock Creek, Missouri River, and Dry Cottonwood Creek
Aaron C. Palke, Nathan D. Renfro, Jeffrey R. Hapeman, and Richard B. Berg

Color Modification of Spinel by Nickel Diffusion: A New Treatment
Michael Jollands, Abadie Ludlam, Aaron C. Palke, Wim Vertriest, Shiyun Jin, Pamela Cevallos, Sarah Arden, Elina Myagkaya, Ulrika D’Haenens-Johannson, Vararut Weeramongkhonlert, and Ziyin Sun
Special Colors and Optical Effects of Oregon Sunstone: Absorption, Scattering, Pleochroism, and Color Zoning
Shiyun Jin, Aaron C. Palke, Nathan D. Renfro, and Ziyin Sun
THE ARCHIVE
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