Diamond Fluorescence

Diamond fluorescence was once considered bad, is it? Well that depends!

Some of the most famous diamonds are fluorescent.

Diamond Fluorescence 

Image credit permission of Ed Searancke of http://www.samarajames.com

Roughly 10% of all diamonds fluoresce when exposed to ultraviolet (UV) light. Almost all (95%) fluorescent diamonds show up as blue.

Diamond Fluorescence 

Image credit permission of Ed Searancke of http://www.samarajames.com

Is Fluorescence Visible?
The strength of fluorescence is noted on the grading report. Faint and Medium fluorescence will only be seen in a darkened room with UV blacklights such as a nightclub, where they’ll take on a soft glow. Strong and Very Strong fluorescence are profoundly visible under UV in a darkened room and, as long-wave UV is an essential component of sunlight, you will often see the effects of Strong and Very Strong fluorescence when the diamond is in natural daylight.

Is Fluorescence Bad?
To Performance: Usually not. But some Strong and Very Strong fluorescent diamonds may take on a milky or hazy appearance, reducing transparency and negatively impacting performance in UV-rich environments, like direct sunlight, discos and the tanning salon.

To Durability: No. Fluorescence does not impact durability.

To Color: No and Yes. Fluorescence can cause some diamonds to appear higher in color under certain lighting. But there is debate concerning GIA’s use of UV in color-grading lighting, implying that fluorescent diamonds may appear lower in color than their GIA grade when no UV is present.

To Value: Yes. The diamond trade devalues fluorescent diamonds, usually relative to the strength of the fluorescence. This results from concerns about transparency, the debate on color-grading accuracy and long-standing negatives surrounding liquidity. DEF colors are penalized more than GHIJ, while lower colors may not be penalized. On the positive side, the “discounted” status of fluorescent diamonds makes them cheaper up-front.
Should I buy a diamond with Fluorescence?

It’s a personal choice. Most people don’t know anything about it. Often a new diamond owner is surprised to see the diamond glow blue when they enter a disco or nightclub. Some people are concerned – thinking it’s a fake or radioactive – and are relieved to learn it’s just natural fluorescence. Some people avoid fluorescence because their jeweler advised against it, or due to their own preference. But there are also diamond enthusiasts and collectors who specifically seek fluorescent diamonds for that natural quality.


The most famous phosphorescent diamond is the 45.52ct Hope Diamond, in the Smithsonian

Call our appraiser today at (303)223-4944 for an appointment or inquire right now by email.

diamond fluorescence