Diamond Fluorescence: What You Need to Know Before You Buy
Diamond fluorescence is one of those aspects of diamonds that can either be a deal-maker or deal-breaker, depending on your perspective. While some might see it as a flaw, others view it as an intriguing characteristic that adds a unique touch to their gemstone. Understanding what diamond fluorescence is, how it affects the appearance of a diamond, and whether it should influence your purchasing decision is crucial for any buyer.
In short: Faint to medium blue fluorescence is harmless and can even enhance face-up colour in I-K diamonds (the blue glow counteracts yellow tint). Strong or very-strong fluorescence may cause slight haziness in D-F colours and reduces price by 10-15%. For F-H colour diamonds, faint fluorescence is the value sweet spot — visually unaffected, modest price discount.
What Is Diamond Fluorescence?
Diamond fluorescence refers to the visible light that some diamonds emit when exposed to ultraviolet (UV) rays. The fluorescence is most commonly a blue glow, though other colours such as yellow, green, or even white can sometimes be observed. This phenomenon occurs due to the presence of trace minerals within the diamond's structure, which react to UV light. Not all diamonds exhibit fluorescence, and its strength can vary from faint to very strong.
The Impact of Fluorescence on Diamond Appearance
The effect of fluorescence on a diamond's appearance can be subjective. In certain lighting conditions, particularly in natural daylight, a diamond with strong fluorescence may appear hazy or oily. However, in other cases, it can actually enhance the visual appeal of the diamond, making it appear more brilliant, especially if the diamond has a lower colour grade.