The Importance of Fluorescence Explained

Diamond fluorescence refers to the intensity of a blue glow that is visible when exposing a diamond to UV light. Under normal daylight, a diamond with a strong fluorescence is likely to look milky and lifeless.

For diamonds with faint or no fluorescence, this does not affect the natural appearance of the diamond but a more fluorescent diamond glows in natural sunlight too and this can be perceived as being undesirable in a white diamond.

The degree of fluorescence can vary as one third of diamonds show some fluorescence, with 95% exuding a blue colour. Next comes yellow with any other colour being very rare indeed.

Yes, fluorescence is one indicator of the quality of your diamond engagement ring but its presence is not necessarily negative. A minor blue fluorescence, for example, can balance a yellowish tint in a diamond making it appear whiter.

Grading Fluorescence

Fluorescence ranges from none through faint to medium, strong and very strong. A strong and very strong fluorescence can sometimes give the diamond a milky appearance which is why at Rare Pink we only offer diamonds of None to Medium fluorescence and in particular recommend fluorescence of None and Faint, depending on the customer's price point.

What Grade For a Quality Diamond?

I recommend diamond engagement rings with fluorescence grades of faint or none, and may occasionally suggest a medium fluorescence for lower colours or to help get a diamond close to a customer’s price point.

When choosing a diamond engagement ring, fluorescence is one thing to consider but I would advise to consider it last or least when compared to the other diamond characteristics described in this guide.

Diamond fluorescence


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