Diamond fluorescence refers to the intensity of a colored glow (usually blue) that is visible when a diamond is exposed to UV light. Under normal daylight, a diamond with a strong fluorescence can sometimes look milky and lifeless. Diamonds with none or a faint fluorescence are rarer than those with a strong or very strong fluorescence.
For diamonds with faint or no fluorescence, this does not affect the natural appearance of the diamond but a more fluorescent diamond glows in natural sunlight too and this can be perceived as being undesirable in a white diamond.
The degree of fluorescence can vary as around one-third of all diamonds show some fluorescence, with 95% exuding a blue color – though green and yellow fluorescence diamonds can also be found, though much rarer than those with a blue hue.
Fluorescence is one indicator or grading variable for a diamond, but its presence does not necessarily affect how a diamond looks.
Fluorescence ranges from none through faint to medium, strong and very strong. A diamond with a strong or very strong fluorescence can sometimes have a milky appearance, although this is exhibited by less than 2% of diamonds with a strong or very strong fluorescence grade.
At Taylor & Hart, we inspect all of our diamonds and only offer diamonds that carry the maximum possible brilliance. In particular, we recommend fluorescence of “none” and “faint” because we believe your diamond should look beautiful in all lighting conditions and these two grades are least affected by fluorescence.
Our consultants are available to help you to better understand the importance of fluorescence in a diamond and how it can affect the look and feel of your diamond ring.