Should A Diamond Have Fluorescence? – Quick Expert Answer

Hey! I finally find the Answer!

If you are searching for the perfect diamond jewelry, whether you’re shopping online or visiting different stores, you will find an astonishing number of diamonds, all confusing in their features and quality profiles.

Most stones will look the same but are priced and described differently. When you ask the jeweler or the salesperson, they will inform you that despite their apparent similarities, they are, in fact, very different from each other because of how they sparkle and also how they look under UV light.

After some time, you will notice that some sparkle more brilliantly than others, with the much cheaper diamonds, will look a little cloudy. Many people don’t notice these differences, though, and if you wish to shave off some bucks, you may opt for the less bright diamonds.

Why all these differences, though? And what element affects the clarity of the diamonds and, ultimately, their pricing? Other than the Clarity level and the cut, the stones’ brilliance may be influenced by something called fluorescence.

Whether diamonds should fluoresce or not is the subject of this article, so let’s get into it.


Should a diamond have fluorescence? What is it?

Should A Diamond Have Fluorescence

Diamonds may or may not have fluorescence, and it’s been recorded that up to 30% of all diamonds will have some degree of fluorescence. But what exactly are we talking about?

Diamond fluorescence is defined as the tendency for diamonds to emit this soft-colored flow whenever the stone is subjected to UV light, like visible or black light.

As mentioned above, about 30% of all natural/ mined diamonds will have some degree of fluorescence. Fluorescence is often seen as blue light. But then, the degree of fluorescence in the particular stone matters, and depending on the color grade and clarity of the diamond, the fluorescence may be seen as a defect.

The degree of diamond fluorescence differs too, and most diamonds have a fluorescence level graded as a faint, medium, strong, or very strong. There are also many other diamonds with no fluorescence, and these have the best natural color properties, meaning they are the most expensive stones.

Should A Diamond Have Fluorescence

Since diamond fluorescence is a natural occurrence, it is beyond anyone’s control unless the inclusions are removed or masked and the clarity level of the diamonds increases.

But generally, a diamond may or may not have fluorescence, meaning that it may or may not luminesce under UV light to emit colored visible light in different strengths.

These diamonds mostly have a blue fluorescence, but there are rare instances when diamonds luminesce different colors like red, yellow, white, or orange.  

Types of diamond fluorescence and their effects

As mentioned above, the fluorescence in diamonds is a characteristic that affects the diamonds’ appearance, and its impact depends on the degree of fluorescence. Fluorescence can be Faint, Medium, Strong, or Very Strong.

Should A Diamond Have Fluorescence

Faint/ None Fluorescence – this doesn’t affect the appearance of the diamonds much, but they may appear only slightly hazy.

Medium Blue Fluorescence – in the case of diamonds with a medium-blue fluorescence, particularly the diamonds in the higher color grades, say G grades or higher, the fluorescence will give such diamonds more of a hazy or milky look.

Strong and Very Strong Blue Fluorescence – this high degree of fluorescence results in very cloudy/hazy diamonds.

It is also important to note that while fluorescence improves some diamonds, others don’t benefit from this quality – this is especially true for the diamonds that belong to the D, E, & F color grades, which also constitute the low-value diamonds.

In the case of fluorescence in the colorless diamonds that fall in the DEF color grades, the value of these diamonds will drop by about 15%.

This is especially true for the diamonds with faint to medium degree of fluorescence, which is also stones whose fluorescence is easily perceptible to gemologists when they view the stones under UV light.

Should A Diamond Have Fluorescence

On the other hand, the blue fluorescence glow in diamonds belonging to the I-M color grades is often an added advantage that increases the value of the diamonds.

The increased value comes from the fact that the color blue complements the color yellow, which is common in most diamonds, so the interaction of these two colors leaves you with diamonds that look much whiter and brighter.

So, any medium, strong, or very strong fluorescence diamonds in the I-M color grades will be valued higher because these diamonds shine the brightest.

In terms of the influence of fluorescence on the quality and the price of the diamonds, you need to be extra cautious when buying diamonds with strong blue fluorescence, especially for diamonds belonging to the D-F color grades or even the diamonds with a very strong blue fluorescence in the G-H color grades.

Should A Diamond Have Fluorescence

This is important because these diamonds don’t naturally have enough body of color to offset the high fluorescence, so these diamonds may not be ideal for you.

Note: Diamonds in the D-F color range are considered colorless, naturally. Diamonds in the G-H color grades are near-colorless, and the I-M color diamonds are warm.


What causes fluorescence in diamonds?

Should A Diamond Have Fluorescence

Fluorescence in diamonds results from interactions between the diamonds’ microscopic and submicroscopic structures in the crystals.

The common blue fluorescence, for example, results from the presence of nitrogen atoms in the submicroscopic structure, all aligned in a specific array in the carbon atoms’ lattice.

This fluorescence is often an identifying feature of the diamond but not a performance feature, and it may be good or bad, depending on the affected diamonds.


How to check fluorescence in diamonds

Should A Diamond Have Fluorescence

To check for fluorescence, you only need to look at the diamonds under UV light, either from a direct UV source, which is what jewelers and gemologists use, or you could hold up the stone under direct, bright sunlight.

Alternatively, you could also detect fluorescence by observing the stone under black light.In the lab, fluorescence is determined using a set of fluorescent master diamonds viewed at specific angles under UV light.

The viewing angle is important because fluorescence may occur only in specific or localized angles/ zones in the diamond, meaning that the fluorescence would be pretty visible from one angle and less visible from another.

So, the emitted light or fluorescence can be directional or multidirectional under UV light.

There also are instances where the fluorescence is localized to multiple areas within the diamond, meaning that the diamonds could either display distinct colors in these spots or even have a mixed color array.

This is unusual, though, and very few diamonds portray such characteristics.


Are the fluorescent diamonds cheaper?

Should A Diamond Have Fluorescence

These diamonds can be cheap or expensive. But first, you should know that fluorescent diamonds are priced differently from non-fluorescent ones.

So, the warmer diamonds with strong fluorescence in the I-M color grades will go for a premium 2 or 3% higher than the non-fluorescent I-M grade diamonds.

This happens because the warmer (yellow-hued) diamonds will have a positive interaction with the blue fluorescence that will cancel out, making the diamonds brighter, hence more expensive.

On the flip side, you have the D-H diamonds, whose color features are dampened by the very strong blue fluorescence, and you may save as much as 15% on these diamonds.

It’s important to note that the pricing of diamonds is entirely mathematical. Though prices fluctuate because of the forces of demand and supply, they are also affected by the diamonds’ characteristics and make.

Some non-fluorescent white diamonds may cost less than the enhanced fluorescent ones.


How much does fluorescence matter in diamonds?

Should A Diamond Have Fluorescence

It depends on the level of fluorescence and the quality of the diamonds. Some diamonds look better with fluorescence, but not all since some are negatively impacted by fluorescence.


 Pros and cons of a diamond have fluorescence

Should A Diamond Have Fluorescence


  • I-M diamonds appear brighter when they have a very strong blue fluorescence, making the diamonds more valuable
  • Some fluorescent diamonds are cheaper than non-fluorescent ones.
  • G-H near colorless diamonds with faint fluorescence will be bumped up one color grade and appear even brighter
  • D-F fluorescent diamonds are up to 15% cheaper.


  • Fluorescence to colorless diamonds, even faintly, will add a blue to the diamonds, lowering their value.
  • You may not notice fluorescence in diamonds
  • High fluorescence results in hazy diamonds


Should you buy a diamond have fluorescence?

Should A Diamond Have Fluorescence

Since the effects of fluorescence on diamonds are neither good nor bad, it is safe to say that you may or may not buy diamonds with fluorescence depending on the level of fluorescence and its influence on the appearance of the diamonds.

To save some money on colorless diamonds, for example, it may be cheaper to buy fluorescent D-H diamonds, especially if you don’t mind that blue spark on the diamonds.

But because the diamonds may look hazy from fluorescence, you may want to avoid diamonds with medium, strong, and very strong blue fluoresce because these often look hazy.



Some diamonds appear hazy, and others are whiter/ brighter from fluorescence. So, before buying fluorescent or non-fluorescent diamonds, determine what you’d like your diamonds to look like and the influence of different fluorescent levels on the diamonds, then make a decision.

Make sure to inspect the diamonds before purchase, and avoid the diamonds whose color features are altered negatively by fluorescence.

And if you don’t mind some haziness for a small price cut, then you may be fine with some of the heavily fluorescent stones.

Hey! I finally find the Answer!