The Truth About Diamond Fluorescence: My Insights from 25+ Years in the Diamond Industry

Hello, I’m Mike Nekta, a diamond and jewelry expert with over two and a half decades in the business. One of the more common questions I get asked, particularly by those considering high-quality diamonds, is whether fluorescence in diamonds affects their appearance and value. Today, I want to share my thoughts and insights on this characteristic and explain why, in most cases, it’s more of a unique feature than something to worry about.

What is Diamond Fluorescence?

Let’s start with the basics. Around 30% of diamonds exhibit fluorescence when exposed to longwave ultraviolet (UV) light. When I talk about fluorescence, I’m referring to the glow diamonds can emit when exposed to UV light, such as sunlight or certain lighting conditions. For 95% of fluorescent diamonds, this glow is blue.

Now, here’s an interesting fact: many lower-color natural diamonds (those with a slight yellow tint) can appear more colorless in sunlight if they have strong or very strong blue fluorescence. The UV light naturally enhances their color, giving them a whiter appearance. But once you step inside to a place like an office with reduced UV, the diamond can take on a slightly different hue. This is one reason why you’ll often see a beautiful transformation in a diamond’s appearance under different lighting conditions.

My Experience with Fluorescence and Diamond Color

In my career, I’ve worked with thousands of diamonds, and I’ve found that fluorescence can sometimes be an asset rather than a flaw. One particular story stands out: years ago, a client came to me looking for an eye-catching diamond within a specific budget. After reviewing several options, I recommended a diamond with strong blue fluorescence. Outdoors, it looked nearly colorless, even though it was technically a lower-color diamond. Under the bright New York sunlight, it dazzled with a crisp, clean appearance that rivaled higher-priced colorless stones. Indoors, it had a slightly warmer tone, which didn’t bother the client at all. She loved it and still tells me how it “transforms” in different settings.

The “Hazy” Fluorescence Myth

Occasionally, people worry that strong fluorescence will make a diamond look hazy or oily. Here’s the reality: less than 0.2% of fluorescent diamonds might display this effect. It happens only when extremely strong fluorescence combines with particular types of nanoinclusions. In my experience, I’ve rarely seen this. Strong fluorescence alone won’t cause haziness.

That said, if a client is particularly concerned about this, I always suggest viewing the diamond under various lighting conditions before making a final decision. After all, a diamond is meant to shine wherever you wear it!

Factors That Impact Diamond Appearance More than Fluorescence

While fluorescence may play a small role in how a diamond looks in different lighting, many other factors influence a diamond’s color more significantly. These include the diamond’s cut, shape, and how it’s set. I often advise clients to try on a diamond with their chosen setting because the metal color can have a surprising effect on the diamond’s appearance.

Then, there’s the environment itself. Colors from your clothing or surroundings can affect how a diamond appears. If you’re wearing a black suit, for instance, the diamond may look a bit brighter against that dark backdrop. There are endless ways a diamond’s appearance can shift, which is one of the reasons I love working with these incredible gemstones. They’re dynamic and ever-changing, much like my clients who wear them.

My Takeaway: Embrace Fluorescence as a Unique Feature

In most cases, fluorescence is a characteristic rather than a flaw. It’s one of those unique aspects that make each diamond distinct, much like individual traits in people. I often tell my clients that a diamond is an extension of their personality, and characteristics like fluorescence only add to its individuality.

now below is a YouTube video from my YouTube.com/mikenekta5 

in the video linked below, you’ll see a super cool demonstration of what fluorescence can do to a diamond. I don’t think you’ll see this anywhere else on the entire Internet because this Diamond is so interesting and special. I don’t wanna ruin the surprise for you so check out the video below..

In closing, remember: diamonds are complex, multi-faceted gems that each have their own “personality.” Whether they fluoresce under UV light or not, every diamond has something special to offer.