diamond flourescence Leon Mege

According to GIA research, up to 35% of all diamonds in the world fluoresce.

Fluorescence is an ability of a diamond to emit a glow when subjected to ultraviolet light (blacklight), just like Fido’s stains do.

Disco lighting, fluorescent bulbs and natural sunlight all have UV component that triggers the glow.

Its intensity depends on the UV light strength and the ambiance lighting.

Faint fluorescence requires a complete darkness to be observed. It is not considered to be detrimental to the value of the diamond.

When we talk about fluorescent stones, we mean those with medium, strong or very strong fluorescence.

Less than half of fluorescent stones are affected - their transparency, brilliance, and fire are somewhat reduced causing them to appear foggy or hazy.

Is there any good reason to buy a fluorescent stone?

Assuming the stone’s look is not affected it is a consideration, when:

There is not enough budget to buy a stone of the desired carat size.

  • It is the only option available in hard-to-find categories, such as antique cuts.
  • You are mesmerized by the glow effect
  • The center stone is I-J color as graded by GIA
  • The stone is very small
  • The stone is not certified (crazy by itself, unless you are a professional or a daredevil, who likes to play Russian roulette.)
  • You are a member of the Vietnamese community where fluorescent stones are valued for their magical properties.


General consensus is to avoid buying a stone with fluorescence.

Just like the discounted cashmere sweater from one of the Seinfeld episodes - no one wants it, although the stain is tiny and barely visible.