Decoding Fluorescence in Diamonds: A Gemologist’s Perspective
By Deepa Srinivasa (Chief Gemologist), GSI
Fluorescence in diamonds is often misunderstood, yet it is a critical factor in distinguishing natural diamonds from their lab-grown counterparts. To begin with, not all diamonds fluoresce. Most are inert and show no fluorescence at all. Approximately 35% of natural diamonds exhibit fluorescence, and among those that do, over 90% fluoresce blue. However, about 10–15% of natural diamonds may fluoresce in other colors, such as yellow, green, or even orange.
The challenge arises because most screening instruments are optimized to detect blue fluorescence, which does not provide a complete picture. Blue fluorescence is not exclusive to natural diamonds; although rare, some lab-grown stones have been observed to show weak bluish fluorescence as well. This is why further analysis is essential. Screening results are only the starting point of the diagnostic process. Interpreting fluorescence correctly requires expertise, as the underlying nuances go beyond what standard instruments can reveal.
Detecting fluorescence becomes even more complex when diamonds are mounted. Metal settings can obscure or mask fluorescence that would otherwise be visible in a loose stone.
An additional layer of complexity appears when the center diamond exhibits stronger fluorescence while the surrounding stones do not. This discrepancy can distort the overall appearance and even mislead professionals. It is a subtle yet significant detail that demands both technical skill and a deep understanding of diamond behavior.
In essence, fluorescence analysis goes far beyond a simple “yes” or “no” detection. It requires a comprehensive approach that combines advanced screening technology, gemological expertise, and precise interpretation of results. Without this level of analysis, key details may be overlooked, potentially compromising the integrity of the classification process.
~ HEERA ZHAVERAAT|NOV 25
