Fluorescence is one of the most confusing aspects of diamonds. It is supposed to be a flaw and yet some sellers prefer their stones to have a certain degree of it. Such dichotomy often clouds our minds. Add to that obscurity of facts, and there you have a perfect under-explored topic strewn with misconceptions and misinformation. The textbook definition separates fluorescence from color. They are not one and the same thing. In fact, they are not even related. They are two different elements. Fluorescence ideally refers to the capacity of a diamond to fluoresce when put under UV light.
Grades and Effects of Fluorescence
Fluorescence in diamonds are of five key grades namely; none, mild, medium, strong and V strong. When exposed to an UV beam, diamonds glow with certain coloration, blue being the most common kind. So how does it impact the quality of a stone? Fluorescence doesn’t really affect the quality of a diamond in most cases, unless of course you are talking about very strong fluorescence. Fluorescence in diamonds is mostly undetectable to the naked eye. That is why stones with none or faint grade fluorescence show little or no change in color. It is when the fluorescence of a stone gets higher than medium that it starts to cause slight to moderate changes in the original color of the stone. This in the end brings down the value of the stone.
Quite unexpectedly, in some rare occasions, fluorescence adds value to diamonds by bringing in a hint of color. Diamonds of I or lower color grades benefit from their fluorescence because it only deepens their otherwise scarce color pigments. Thus, by endowing some stones with a stunningly brighter appearance, fluorescence lends value to some diamonds.
Fluorescence of a diamond shows only under UV light and we all know that sunrays have UV in them. So, does that mean fluorescence in diamonds reveals itself when exposed to sunlight? A blanket answer would be no, although the results are variable in different cases. For a stone with a very high fluorescence, the sunlight does help in bringing it out, but for most the effect is too mild, particularly when the beams hit glass and other surfaces before entering the stones. So, if a little fluorescence brings down the price by a considerable margin, don’t be afraid to grab the deal. A little sunlight will not reveal anything embarrassing about your sparkler.