Diamond Fluorescence for beginners

Diamond fluorescence is a non-issue for most people buying diamonds, but the misconception surrounding the term can cause confusion. If you’re shopping for a diamond or noticed the term ‘Fluorescence’ on a diamond grading report and you’re not sure whether it’s good or bad, this article’s for you.

When it comes to diamonds, the Gemological Institute of America, better known as the GIA, is the go-to authority. Below is the GIA definition of Fluorescence;

“Diamond fluorescence, in its most simple form, is the effect that ultraviolet (UV) light has on a diamond. Fluorescence is the visible light that a diamond emits when it is exposed to UV rays (Ultraviolet light has a similar effect on our teeth). The light emitted lasts as long as the diamond is exposed to the ultraviolet source.”

A diamond will acquire its fluorescent quality when trace elements of aluminium, boron, or nitrogen are absorbed by a diamond as it forms. The majority of diamonds do not fluoresce. In a study of more than 26,000 diamonds submitted for grading to GIA, only approximately 25% to 35% exhibited some degree of diamond fluorescence when examined with a standard long-wave UV lamp. However, only 10% of those show strengths of fluorescence that may affect appearance (i.e., strengths noted on laboratory reports as medium, strong, or very strong).

In a GIA fluorescence study, it was found that the average person could not see a difference between a diamond with fluorescence and a diamond without, because the overwhelming majority of diamonds tested had a strength of fluorescence that had no noticeable effect on the appearance of the diamond. However, in rare cases, some diamonds with extremely strong fluorescence appeared hazy or oily, although fewer than 0.2% of the fluorescent diamonds submitted to GIA exhibit this effect.

In summary;

1. Fluorescence is visible in some diamonds only under UV light
2. Fluorescence doesn’t compromise the structural integrity of the diamond
3. Diamond fluorescence is not one of the 4Cs which describe the quality of a diamond. GIA considers fluorescence an identifying characteristic – additional information that helps distinguish one diamond from another.
4. Diamond fluorescence has little to no effect on a diamond’s sparkle, and research shows that it doesn’t impact beauty either.

Now that you have the facts on Fluorescence, my recommendation would be that you compare diamonds in a variety of lighting environments and select the diamond that most appeals to you. Every diamond is unique, and the beauty remains in the eye of the beholder.

*Credit: the majority of this article’s content was adapted from the GIA website