Is Diamond Fluorescence Good or Bad?

Diamond fluorescence is a fascinating topic that is surrounded by many misconceptions. Some people have heard that fluorescent diamonds should be avoided at all costs. And some people have never heard about diamond fluorescence.

So is diamond fluorescence good or bad?

The answer is: It depends!

I will explain to you what that means and under which circumstances diamond fluorescence is good and under which circumstances it is bad. Let’s get to it in an orderly fashion.

What is diamond fluorescence?

In general diamond fluorescence describes a diamond’s response to ultraviolet light. UV light can usually be found in sunlight, fluorescent bulbs or in night clubs.

Diamond Fluorescence good bad

Now, diamonds contain elements such as nitrogen, aluminium and boron. When these elements are subjected to UV light, they absorb that energy and jump to a higher energy state. In order to stay in a physically stable state, these elements will have to emit all the excess energy. They do so by releasing light which is perceived as fluorescence.

The most common fluorescence color in diamonds is blue which applies to around 98% of all diamonds with fluorescence. There are however also diamonds with white, yellow, green or even pink fluorescence. Ultimately, the color of diamond fluorescence is decided by the physical make-up of a diamond’s inner atomic structure.

So, when is diamond fluorescence good or bad?

Diamond fluorescence can be good for the following reasons: Diamonds with fluorescence are around 10% – 15% cheaper, they can face up whiter and the fluorescent effect under UV light can be very impressive and make your diamond look very special.

At the very same time diamond fluorescence can also be bad because it can sometimes cause haziness in a diamond. This would translate into milky spots that can be seen with your bare eyes in a diamond. Such diamonds are also referred to as overblue diamonds.

You see, this is is the reason why I said it depends whether diamond fluorescence is good or bad. In cases where the fluorescence does not cause any haziness the fluorescence would only have pros.

Now, diamonds with blue fluorescence do have a somewhat bad reputation and for this reason blue fluorescent diamonds tend to be cheaper. In reality the bad reputation is completely unfounded, though.

It is due to the fact that some decades ago so-called “blue white” diamonds with blue fluorescence were sold on the market and demanded a premium price. It originally only applied to high quality diamonds but was then also used by salespeople to market lower quality diamonds with blue fluorescence. This lead to the Federal Trade Commisson of the USA to ban the “blue white” descriptive label. Ever since then diamonds with blue fluorescence had a bad reputation.

I will show you systematically how you can take advantage of the pros while not suffering any disadvantages of the cons of diamond fluorescence.

Are fluorescent diamonds milky, hazy or oily?

There are different grades of fluorescence, namely none, faint, medium, strong and very strong fluorescent diamonds.

Diamond Fluorescence scale

In my experience

  • Faint blue fluorescent diamonds are never hazy
  • Medium blue fluorescent diamonds are usually not hazy
  • Strong/Very Strong blue fluorescent diamonds are usually hazy

So what does that mean?

It means that you can always take a diamond with faint fluorescence – it will not make any difference to the diamond. And you can save some money on the diamond.

As I have also described in my post about diamond color you should especially consider medium blue fluorescence for H, I, J or K color graded diamonds. This can have the effect of making your diamond appear whiter. This effect will always be particularly pronounced when you submit your diamond to daylight which is a natural source of UV light.

For the colorless range from D – F there there is no such effect of the body color of the diamond appearing whiter.
Now, as strong or very strong blue fluorescence usually makes a diamond appear hazy I would not recommend buying such a diamond unless you can inspect it first! Particularly diamonds within the D – F range are very prone to appearing hazy when combined with strong or very strong blue fluorescence:

Colorless diamonds with strong blue fluorescence appear hazy

A great place to buy diamonds with blue fluorescence is James Allen! No other place will let you view ALL of its diamonds in high definition 360° videos in 40x magnification! This way, it is is pretty safe to pick a diamond with fluorescence and no haziness.
If you want hearts and arrows diamonds with blue fluorescence go and check out Brian Gavin’s Blue signature line diamonds. All diamonds have been picked by Brian Gavin personally to have a superior optical performance without any traces of haziness.

The bottomline with diamonds with blue fluorescence, particularly strong and very strong blue fluorescence is to either inspect the diamond yourself or buy from a reliable vendor like Brian Gavin.

But why is there so much confusion surrounding diamond fluorescence?

The main reason for confusion on diamond fluorescence is a study performed by GIA in 1997. The conclusion of this study was that “fluorescence had no over-all effect on color appearance or transparency”.

However, the same study also noted that the observations showed a clear trend for weakly fluorescent diamonds to be considered more transparent than strongly fluorescent stones (page 256, figure 7).

And the study also does not deny that 50% of all participants did notice a difference in transparency in fluorescent and non-fluorescent diamonds.

result of GIA study on diamond fluorescence

Check out the study for yourself if you want to. I find the study’s conclusion quite contradictive and all in all not really representative.
Thus, if someone wants to tell you that GIA has proven that diamond fluorescence does not have any negative effect, think twice!

Pros of blue fluorescent Diamonds

Once you have made sure to follow my advice above you can enjoy the benefits of a blue fluorescent diamond. One of these benefits is the fact that most blue fluorescent diamonds are cheaper than a comparable diamond without the blue fluorescence.

Furthermore, you get to have a diamond that exhibits blue fluorescence! In usual lighting conditions you are not able to tell any difference. But once the diamond gets exposed to some fluorescent light the diamond begins to shine in an icy blue way.

In the video below you can see an example of a diamond from the Brian Gavin Blue signature line:

In the end it is just a pure matter of taste whether you prefer to have a usual diamond or one with blue fluorescence.

The blue fluorescence of a diamond can definitely add some soul to the diamond and make it stand out more. Whether you might want to buy a diamond with blue fluorescence is entirely up to you.

I would just recommend to stick with the guidelines I have provided and you will definitely have a diamond that you can enjoy for a long time.

If you have any more questions just drop me a comment or write me a mail!