On the occasion of its 90th Anniversary, the Winter 2024 Edition of Gems & Gemology (Volume 60, Issue 4) celebrates excellence in advanced gemological investigation. This special issue offers a comprehensive overview of the most sophisticated techniques employed in modern laboratories to address the increasingly complex challenges of gemstone identification.
The opening article, “Application of UV-Vis-NIR Spectroscopy to Gemology”, authored by Shiyun Jin, Nathan D. Renfro, Aaron C. Palke, Troy Ardon, and Artitaya Homkrajae, delves into the use of UV-Vis-NIR spectroscopy. This technique, one of the most significant in gemology, examines how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared regions. Through a detailed analysis of absorption spectra, essential information is obtained regarding the composition, origin, and treatments of gemstones. The article illustrates practical applications of the technique in the analysis of colored stones, fancy color diamonds, and pearls, with a particular focus on determining variety, origin, and identifying complex treatments.
The issue continues with “Chemical Analysis in the Gemological Laboratory: XRF and LA-ICP-MS” by Ziyin Sun, Michael Jollands, and Aaron C. Palke, which describes the application of X-ray fluorescence (XRF) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). These techniques provide highly detailed and sensitive chemical analyses that are fundamental for determining the origin of gemstones and identifying any treatments. The article offers an in-depth look at how these technologies are used to analyze precious stones, with practical examples illustrating their importance in gemstone classification and authentication.
A particularly intriguing contribution is “Glowing Gems: Fluorescence and Phosphorescence of Diamonds, Colored Stones, and Pearls” by Ulrika F.S. D’Haenens-Johansson, Sally Eaton-Magaña, W. Henry Towbin, and Elina Myagkaya. This article explores photoluminescence imaging to analyze the phenomena of fluorescence and phosphorescence in diamonds, colored stones, and pearls. The ability of gems to emit light when exposed to ultraviolet radiation provides valuable insights into the chemical and structural identity of gemological materials, helping to distinguish between natural, synthetic, and treated stones.
This edition also pays tribute to two important figures in gemology, Alan Hodgkinson and Glenn Lehrer, commemorating their contributions and the legacy they have left to the world of gemstones — a heartfelt homage to those who have dedicated their lives to understanding and enhancing the value of precious stones.
The Winter 2024 edition of Gems & Gemology Vol. 90 is available for online reading and free PDF download on the official website.
