A Beginner’s Guide to Diamond Fluorescence

April 23, 2023

Diamonds are fascinating, both in their natural state and when expertly crafted into beautiful pieces of jewelry. Each stone is unique in its own way, whether they grow to shocking sizes and weights, take on unusual color, or exhibit other fascinating characteristics. Diamond fluorescence falls into the latter category - it’s a captivating trait only shown in about a quarter of all diamonds.

What is Diamond Fluorescence?

Fluorescence refers to the phenomenon of some atoms absorbing light of one wavelength and subsequently emitting light of a different wavelength. What does that have to do with diamonds? Well, some diamonds fluoresce exactly like that! They absorb ultraviolet light and then emit a blue-tinted light. In very rare instances, diamond fluorescence appears as red or yellow, but that accounts for 5% or less of all fluorescent diamonds.

Fluorescence is only visible during exposure to UV light. In other conditions, it doesn’t typically affect the diamond.

How Important is Diamond Fluorescence in Diamond Grading?

The short answer is that diamond fluorescence doesn’t matter for grading. It isn’t included among any of the 4Cs, so won’t affect that final stamp of Excellent, Very Good, and so on.

With that said, there are ratings for fluorescence. Depending on the intensity of a diamond’s fluorescence, it receives one of the following scores: none, Faint, Medium, Strong, and Very Strong.

diamond fluorescence

Although fluorescence doesn’t affect the grade of your diamond, its presence (or lack thereof) is part of the overall description. If you already know whether or not you’re a fan of fluorescence, having the information readily available is helpful. Personal preference is the biggest factor in fluorescence - you either like it or you don’t. Either way, it won’t affect your diamond’s grade.

How Does Diamond Fluorescence Affect a Diamond's Appearance?

Several aspects of a diamond’s appearance are visible to the naked eye. Clarity and color, for instance, are visible with minimal effort. Cut and carat are simple to determine. Fluorescence, on the other hand, isn’t really visible in normal light. You’ll only see it when observing the diamond under UV light, as that’s how the tell-tale glow activates. All cuts and shapes are affected equally, too, so you’re just as likely to find a fluorescent emerald-cut stone as you are a marquise-cut diamond.

There are several misconceptions about fluorescence’s effect on a diamond’s appearance. Some work in favor of the phenomenon while others assume it has a negative effect on how the diamond looks. Below are several incorrect assumptions about fluorescence.

  • It makes diamonds whiter - While very strong blue fluorescence could potentially make pale yellow diamonds appear clear and colorless, that’s a rare exception and not the rule. It’s more common for fluorescence to have no effect on a diamond’s appearance unless it’s under strong ultraviolet light.
  • It causes haziness - Fluorescence does not cause haziness. In rare instances, it might enhance haziness caused by certain defects, but those defects are at fault. Fluorescence does not diminish appearance in and of itself.
  • It causes an oily appearance - Like haziness, this just isn’t true. While some people firmly hold onto the idea that strong fluorescence causes an oily or hazy appearance, the presence of either of those is the result of something else happening with the stone.

In truth, fluorescence is only visible under specific conditions. It’s a non-entity the rest of the time, and the odds are against average customers (and even professionals) noticing it. Still, viewing your diamond in person is best. You can form your opinion on fluorescence, and all the other important aspects of appearance, for yourself.

How Is Diamond Fluorescence Measured?

Fluorescence isn’t visible in certain light, and it isn’t easy to spot at a glance, but it is fairly simple to measure. Labs use UV spectrum lights and compare diamonds to the set parameters for each grade. As mentioned above, fluorescence is given one of a few possible labels, ranging from none to very strong.

Most diamonds receive a rating of None for fluorescence. Very Strong is the least common rating, with most fluorescent diamonds falling toward the milder end of the scale.

Diamonds are rated on the same scale regardless of the color of their fluorescence, although most of them emit blue light. Red is the least common diamond fluorescence color.

Can Diamond Fluorescence Affect the Value of a Diamond?

Unfortunately, the answer is yes. Because of the misconceptions mentioned earlier, fluorescence sometimes impacts diamond value. Many people continue to hold to the idea that it (negatively) affects the appearance and alters clarity and color. As a result, highly fluorescent diamonds often have less value than non-fluorescent stones of the same grade.

Value, like beauty, is in the eye of the beholder, however, and some people love the appearance of fluorescent diamonds. If you fall in love with a diamond and enjoy its fluorescent appearance, don’t let misconceptions and incorrect ideas halt your purchase. An Excellent fluorescent diamond is still an Excellent diamond at the end of the day, and its cut, clarity, color, and carat remain unaffected.

Diamond shopping and selection is a matter of opinion. It’s helpful to have grades and other information to guide you, but they can’t tell you what you’ll feel or think when you see the diamond in person. If you’re basing your purchase on perceived value alone, though, then a strongly fluorescent diamond might not be the best choice.

Final Thoughts

There is no right or wrong when it comes to fluorescence. It’s present or it isn’t, and people either like it or they don’t! It’s quite interesting, conceptually, but that doesn’t mean it’s for everyone.

Trust the experts at Yadav Diamonds and Jewelry to guide you through your diamond selection. Whether you’re looking for an engagement ring or shopping for fine jewelry, you’ll choose from a stunning collection. Schedule a consultation to get started!

Recent Posts
previous arrow
next arrow
This website uses cookies to ensure your best shopping experiencie and track your cart.Learn More