Diamond fluorescence? what is this, why does this occur and is it good or bad? Firstly lets look at the definition;

Fluorescence: is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation.

Source: Wikipediadiamond fluorescence courtesy of briangavindiamonds.com

Now that we have the definition of fluorescence, let’s look at a diamonds fluorescence. Under certain lighting situations more than one third of all diamonds have some form of fluorescence.

Some of the colors seen include yellows, orange, white/cloudy and by far the most common ‘Blue’.

Image right: an actual image of fluorescence in a 1.115ct I VS2 Signature Blue Princess from Brian Gavin Diamonds.

Graded as a Strong Blue – http://www.briangavindiamonds.com/diamonds/diamond-details/1.115-i-vs2-princess-diamond-ags-bl-104078379016

Brian Gavin is also a strong believer that fluorescence is a positive thing, in fact so much so he has created a line of diamonds with mid to strong fluorescence. To learn more about Brian Gavin’s Blue range of specially selected diamonds click here – “Brian Gavin Blue”  Diamond fluorescence is determined from a scale indicating None (no fluorescence) through to Faint, Medium, Strong and Very Strong. The intensity of a diamonds fluorescence is not specifically relevant to the colour or clarity of any particular diamond, meaning that the colour and clarity have no have an effect whether the diamond will have fluorescence or not. Diamonds of different colours and clarities could also have exactly the same degree of fluorescence.

With anything that is liked by some and disliked by others there is a reason behind it besides personal taste. Fluorescence can affect diamonds positively by making them appear a brighter white and a good ‘face up’ stone in relation to their possible lower graded color. On the other hand fluorescence may cause your diamond to have a “creamy/milk” effect and may affect the brilliance slightly. This is more often seen in very large diamonds and with colours ranging down from “I”. This is of course only when exposed to UV elements, like a Black Light in a night club or example or in full and direct sunlight. All this said only 0.2% exhibit this. Your diamond certification will assist you in identifying this, by looking for the fluorescence and be wary of the Inclusion Term “CLOUDS”.  Clouds within a diamond tend to display a milky appearance under the effects of  fluorescence.

Buying a diamond with fluorescence

For decades when looking for diamonds for sale, ‘fluorescence’ has been deemed unfavorable by both consumers and the diamond industry. For that reason alone they are usually a great buy and should definitely be strongly considered because they tend to be undervalued in my opinion.

Here is a perfect example of what I mean, these diamonds below are available for purchase from James Allen at the time of writing. They all weigh 1.01/1.02 carats each, they are nearly identical in every way all Triple EX Cut, F Color, VVS2 Clarity, Table Angle, GIA Certified but the centre diamond has a STRONG diamond fluorescence.


Even at face value from the images you would have to agree that the centre diamond appears to have a very nice cut, clearly displaying the ‘arrows’ configuration.  Not only does it look a little better but choosing a diamond with fluorescence could save you a minimum of $1200 in this instance.