What is fluorescence?
Fluorescence is an emission of light or glow from a diamond when exposed to UV light.  When diamonds are placed under a UV lamp, some diamonds will glow blue, orange or green and sometimes not at all.  Diamonds can fluoresce in all colors of the rainbow, but they will usually glow in varying shades of blue.  

Do all diamonds show fluorescence?
No, not all diamonds show fluorescence.  It is said that approximately 35% of diamonds show some degree of fluorescence.

What causes fluorescence?
Fluorescence is caused by the interaction between UV energy radiation and the diamond’s atoms. Fluorescence can be seen the strongest under a UV lamp, but in some cases, UV rays from the sun can make a diamond fluoresce.

How does fluorescence affect the way a diamond looks?
It is said that some diamonds that have very strong fluorescence will make the diamond appear oily in regular light.  Diamonds that fall in the J-Z colour grade range may appear less yellow if they fluoresce blue as blue color may cancel the yellow tone in the diamond to have a positive effect on the color.  In some extreme cases, a strong fluorescence in a diamond may have a bluish hint to it if it is in the D,E,F or near colorless range.  It was once believed that fluorescence affected the transparency of a diamond, but with advanced scientific research, that theory has been disproven.  Experts in the industry have concluded that it is nearly impossible to detect fluorescence with the naked eye. 

Does fluorescence influence the price of the diamond?
For many years, it did have a negative effect on the diamond’s value.  After much scientific research, it has been concluded that depending on the strength of the fluorescence, it should not affect the way a diamond appears and therefore should not influence the price.  If the diamond is in the D,E,F range and has strong fluorescence, it may have a negative effect on the price, on the other hand, if the diamond is in the J-Z range with strong fluorescence, it may look less yellow and ultimately have a positive effect on the price.

Fluorescence is a characteristic of a diamond and can help identify a diamond.  As clarity characteristics are known for being the diamond’s ‘fingerprint’ and may help distinguish a diamond, as will fluorescence.  If you have a diamond that does show the property of fluorescence you can distinguish it by simply holding it under a UV lamp and watch it glow.