What is fluorescence? Is it good or bad?



What is fluorescence? Is it good or bad


Some diamonds fluoresce, which mean they emit light when exposed to long-wave ultraviolet light. Diamonds with strong fluorescence, called “overblues,” can sometimes have a hazy appearance that makes them appear cloudy in light with strong ultraviolet content.  On the other hand, strongly fluorescent diamonds with a yellowish body color may seem to have a better color because the blue fluorescence makes them appear whiter in sunlight, which is a source of ultraviolet light.

The Gemological Institute of America lists fluorescence as an identifying characteristic, not a grading factor.

If you are ever at the Smithsonian Institution in Washington D.C., you can see the most famous example of an overblue: the 127 carat Portuguese Diamond. While you are there, make sure to visit the famous Hope Diamond, which owes some of its legendary curse to the fact that it fluoresces an extremely unusual red, which is only known to happen in blue diamonds.

Wishing you a sparkling day!
Diamond Mike Watson



Do you have a jewelry-related question for Diamond Mike? Let us know here, or by emailing info@galleryofdiamonds.com.

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