Understanding Diamond Fluorescence

Understanding Diamond Fluorescence

Diamond fluorescence commonly overlooked when diamond shopping. Have you sometimes noticed the term “Fluorescence” on a GIA Grading Report? Did you know that some diamonds show effects under ultraviolet light?

For most people who purchase diamond jewellery, fluorescence will be a non-issue.

What is diamond fluorescence?

In its most simple form, is the effect that ultraviolet (UV) light has on a diamond. When you stand under a blue light or ultraviolet light you can see your whites get brighter or your teeth appear to glow. This is the same effect the diamond has under the UV rays. When it is exposed to the UV rays Fluorescence is the visible light that a diamond emits .

On a GIA Grading Report, fluorescence refers to the strength, or intensity, of the diamond’s reaction to long-wave UV, which is an essential component of daylight. The light emitted lasts as long as the diamond is exposed to the ultraviolet source.

diamond fluorescence

Is fluorescence common?

Yes. Of the sparklers submitted to GIA over the past decade, approximately 25% to 35% exhibit some degree of fluorescence. Only 10% of those show strengths of fluorescence that may affect appearance. Fluorescence strengths noted on laboratory reports as medium, strong, or very strong.

Blue is the visible colour in more than 95% of the diamonds and therefore is the complementary color to yellow the most common tinted color in diamonds.  Fluorescence which is blue can make yellowish diamonds look white or colorless but the reaction to fluorescence can be yellow, white or another color.

What impact does fluorescence have on the appearance of a Jewel?

GIA studies show that for the overwhelming majority of sparklers, the strength of fluorescence has no widely noticeable effect on appearance. Studies have found that the average person could not make a distinction between a Gem with fluorescence and a Gem without.

Many observers prefer the appearance of stones that have medium to strong fluorescence. Some diamonds with extremely strong fluorescence may appear hazy or oily.  Fewer than 0.2% of the fluorescent diamonds submitted to GIA exhibit this effect.

Does fluorescence compromise the structural integrity of the Rock?

No. A diamond that fluoresces has the same integrity as one with no reaction to UV. Submicroscopic substitutions and/or shifts in the diamond structure can cause fluorescence or can prevent it. Nothing inherently weakens or is bad for the diamond.

Should I buy a diamond that exhibits fluorescence?

The preference to buy a stone that exhibits fluorescence is a personal one. Other factors can influence color appearance more strongly than fluorescence, such as how the diamond has been cut [link to cut posting], whether the diamond is viewed in natural or artificial light, and even what you’re wearing on any given day.

diamond fluorescence

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