Let’s break down diamond fluorescence: everything you need to know!

Today I would like to discuss a largely unknown but extremely important topic in diamond evaluation: fluorescence.

What is fluorescence?
It is a reaction phenomenon that occurs in a diamond when it is exposed to ultraviolet (UV) light. This reaction consists in the diamond emitting light, usually blue in color.

Is fluorescence present in all diamonds?
Absolutely not. It is a characteristic of the diamond that may or may not be present. Like all other characteristics of this wonderful stone, its presence is influenced by the processes that occur during the creation of the diamond and the environment in which this process takes place.

Is the fluorescence always the same or does it have different degrees?
As clearly illustrated in the table below, fluorescence has different levels of intensity, which must be evaluated and determined by a professional gemologist through observation of the stone exposed to UV light. It starts from a degree of "NONE", which indicates the absence of reaction, in which the stone remains inert under exposure to UV rays. "WEAK" indicates a slight reaction, which progressively increases to "STRONG" or even "VERY STRONG", where the stone exhibits such intense fluorescence that it lights up like a light bulb.

That said, let's move on to another very important question to conclude our discussion:
Can fluorescence change or affect the color of a diamond?
The answer is yes, and to fully understand this aspect, we must remember some notions about primary colors learned during childhood. In fact, a well-accentuated blue fluorescence can reduce some yellow tones present in the stone. As you may know, a yellow tone in the color of a diamond is a negative aspect, since it lowers its position in the color classification scale.

So, given these premises, is fluorescence a positive element for a diamond and its valuation?
The answer may surprise you, given what we have just discussed, but fluorescence is a negative characteristic in the evaluation of a diamond. Although it may be fascinating to some, gemologists are unfortunately forced to deduct from the final value of the stone if it exhibits fluorescence.