Does fluorescence lower a diamond's value?

Strongly fluorescent diamonds often sell at a discount, which can be good value if the stone still looks clear. For lower colour grades (I–M), blue fluorescence can actually improve appearance.

Should I avoid fluorescent diamonds?

Not necessarily — judge each diamond in person. Faint-to-medium fluorescence is generally fine or beneficial; only avoid strong or very strong fluorescence if it makes the stone look milky.

What is Diamond Fluorescence?

Q: What is diamond fluorescence?

Fluorescence is the soft glow, usually blue, that some diamonds emit under UV light. GIA grades it None, Faint, Medium, Strong or Very Strong. It is caused by trace elements in the diamond.

Q: Is diamond fluorescence good or bad?

For most diamonds it has no visible effect, and faint-to-medium blue fluorescence can even make near-colourless stones look whiter. Only strong fluorescence in high-colour diamonds may cause a hazy look.

Quick Answer

Does diamond fluorescence matter?

Fluorescence is the soft glow some diamonds emit under UV light, graded from None to Very Strong. In most diamonds it has no visible effect, and faint-to-medium blue fluorescence can even make near-colourless stones look whiter. It only becomes a concern (a hazy or milky look) in a small number of strongly fluorescent, high-colour diamonds — which often sell at a discount.

Reviewed by Winnie GIA-certified Gemologist Updated Jul 15, 2026

DIAMOND FLUORESCENCE

Diamond fluorescence response is a natural reaction. Different gems will also appear fluorescence. Some diamonds when they are exposed to ultraviolet light, visible light will be emitted, this is the diamond fluorescence.

WHAT IS DIAMOND FLUORESCENCE ？

Diamond fluorescence response is a natural reaction, the tomb was different and gem will appear. Some diamonds when they are exposed to ultraviolet light, visible light will show, this is the diamond fluorescence response. In most, different lighting conditions, diamond fluorescence is not seen with the naked eye, except that UV light, will be issued a slight light.