What is a Diamond’s Fluorescence, and Should You Be Concerned?
in grading reports or descriptions. But what exactly does it mean, and does it affect the quality or beauty of a diamond? Let’s explore what fluorescence is, its impact on appearance, and whether it should be a factor in your purchasing decision.
What is Diamond Fluorescence?
Fluorescence is a natural phenomenon that occurs when a diamond emits a soft glow—usually blue—when exposed to ultraviolet (UV) light. This effect is caused by the presence of trace elements within the diamond’s structure that react to UV rays. Once removed from the UV source, the fluorescence disappears.
Fluorescence is graded by gemological laboratories like GIA on a scale ranging from ‘None’ to ‘Very Strong’. Approximately 25-35% of diamonds exhibit some degree of fluorescence, with varying intensities.
Does Fluorescence Affect a Diamond’s Appearance?
The impact of fluorescence on a diamond’s appearance depends on several factors:
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In Colourless Diamonds (D-F Grades): Strong fluorescence can sometimes create a hazy or milky effect, reducing the diamond’s brilliance and clarity.
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In Near-Colourless Diamonds (G-J Grades): Fluorescence can sometimes enhance the diamond’s whiteness by counteracting yellowish tones, making it appear brighter in natural light.
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In Lower Colour Diamonds (K and Beyond): Blue fluorescence can have a positive effect by neutralising warm tones, improving the perceived colour.
Should You Be Concerned About Fluorescence?
Fluorescence is neither inherently good nor bad—it depends on the individual diamond. In many cases, faint or medium fluorescence has no noticeable effect on a diamond’s appearance. However, strong fluorescence in a high-colour diamond (D-F) may result in a slightly cloudy or oily look.
If you’re considering a fluorescent diamond, it’s best to view it in multiple lighting conditions. Some diamonds with strong fluorescence look perfectly clear and beautiful in natural light, while others may exhibit a milky effect under strong UV exposure.
Can Fluorescence Impact Price?
Yes, fluorescence can affect pricing. Since some buyers are wary of it, diamonds with strong fluorescence are often priced lower than non-fluorescent diamonds of the same grade. This means you might be able to find a beautiful, high-quality diamond at a slightly lower cost if fluorescence is present but does not negatively affect the stone.
Final Thoughts
Fluorescence is just one of many factors to consider when choosing a diamond. Instead of dismissing it outright, focus on how the diamond looks in person under different lighting conditions. If the stone is bright and beautiful to your eye, fluorescence is nothing to worry about. Ultimately, a diamond’s beauty is determined by its cut, clarity, and overall visual appeal—fluorescence is just a small piece of the puzzle.