Is Fluorescence in Diamonds a “Bad” Thing?

By Bianca Kawecki June 18, 2015

Recently, I was in a lecture hosted by the GIA (Gemological Institute of America) Alumni Association and AGS (American Gem Society) Guild of South Florida given by Art Samuels, GG GIA, in which he asked the assembled group of many gemologists and jewelry industry professionals, “Is fluorescence in diamonds a bad thing? Would you personally buy a diamond with ’strong‘ fluorescence to give to your future spouse?” The practically unanimous answer was a resounding “No!”

So, what does his question mean? Basically, diamond fluorescence is the effect a diamond has under ultra-violet (UV) light. Approximately one-third of all diamonds exhibit this natural quality that occurs when trace minerals found within each individual stone react in a particular way when exposed to UV light. It’s the same effect as when your teeth appear whiter or when your white clothing glows purple under a night club’s blue-light, for example.

Samuels shared that while it may be taught by schools like GIA that strong fluorescent should be avoided, the actual truth has a little caveat. Strong fluorescence in a colorless diamond may make it appear hazy or oily,thus affecting its beauty. This is why most people shy away from it. Since only about 33 percent of diamonds even exhibit fluorescence, there are only a few cases where it affects their good looks in such a manner.

Since about 95 percent of all diamonds that do fluoresce do so in a blue tone and blue is the complementary color to yellow, the most common tinted color in diamonds, blue fluorescence can make yellowish diamonds look white or colorless in daylight. How does fluorescence affect price? The three components to diamond pricing are size, color and clarity. So. Obviously, slightly off-colored diamonds are less expensive than colorless ones. But when you have a J-K graded diamond that looks like an H-I in daylight, that’s a good thing for the buyer. Fluorescence in this case can save money when you utilize this natural property of diamonds to your financial advantage.

The other great aspect of this quality is that you then don’t need a GG degree to know if your diamonds are “real”. If you head into a nightclub and your gemstone has some fluorescence, you know it’s not a Cubic Zirconia or Moissanite, which do not exhibit this quality at all. That can’t be bad either,right?

Share and Enjoy