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Fluorescence <The Ultimate Diamond Buying Guide>

*Do note that our writings are based on our personal opinion and only serves as a reference or guide.

In this article, we will explain how fluorescence will affect a diamond's overall colour and prices. Also, understand how are diamonds with fluorescence perceived in the resale market.


Fluorescence is the glowing effect that a Diamond has when ultra-violet light is shined onto it. The most common colour is blue, while red, green, yellow is uncommon. Unknown to many, fluorescence greatly affects Diamond prices. It is graded from Very Strong, Strong, Medium, Faint, None.

Keeping all the other variables constant, a none fluorescence diamond can be 10-20% more expensive than a medium fluorescence diamond. Therefore, we see many prices discrepancies in the retail market where some diamonds seem to be selling at a huge discounted price, because they usually have strong or very strong fluorescence.


Diamonds with medium to very strong fluorescence may show a cloudy hazy appearance, but this is uncommon and only happens to less than 10% of the diamonds. According to GIA, only 25% to 35% of diamonds have some degree of fluorescence. Out of that percentage, only 10% have enough fluorescence to actually affect the appearance.

In the picture below, the diamond on the left shows a normal diamond, while the diamond on the right has a cloudy hazy appearance.

Specifically, faint blue fluorescence may also make a diamond (G-H) colour appear visually less yellow, therefore looking like a (F) colour, as the blue and yellow colours cancelled out each other. However, do note that the fluorescence grading does not affect diamond colour grading at all.

From our experience in the resale market, medium to very strong fluorescence diamonds are valued at a much lower price compared to faint or none fluorescence. In our opinion, if your diamond is meant to be kept forever (you won’t sell it or upgrade/exchange it), you can settle for a medium or strong fluorescence as long as it is not cloudy, and prioritise other aspects like getting a bigger diamond instead.

Unusual Fluorescence Colours

Unusual fluorescence colours may give a diamond a unique appearance even without being placed in a UV box. We love coloured diamonds with very strong unique fluorescence colours as sometimes it enhances the body colour even under normal lighting.

Our 2.03 ct Fancy Intense Green Yellow Diamond looks as if it has a neon fancy vivid green colour because of its extremely unique Very Strong Green fluorescence. View our High Jewellery Wynyard Collection to read more about it.

Upon reading our article on fluorescence, it is important to really know what you are looking for and what you prioritise, be it cost savings or a good resale value, if you are trying to get the best diamond for your requirements.

Head back to our Ultimate Diamond Buying Guide to learn about the other components of diamond grading.


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