What's the fluorescence?
One of the lesser-known characteristics of diamonds, the fluorescence response is often misunderstood. In fact, diamond fluorescence is a simple natural reaction that occurs in about 30 percent of all diamonds, causing them to glow under ultraviolet (UV) light. Diamond fluorescence is usually blue, but can appear in a variety of colors, including yellow, orange, red, white or green.
In a small percentage of diamonds (less than 0.02%), fluorescence can make the stone look cloudy or oily, which some consider an undesirable characteristic. In other cases, fluorescence may give some diamonds a chromatographically whiter appearance, which is considered valuable. Because of this, it is necessary to put more effort into understanding whether strong fluorescent reactions in diamonds are good or bad.
Diamond fluorescence response standard and GIA
Unlike the 4Cs (color, cut, clarity, and carat), the Gemological Institute of America (GIA) does not consider a diamond's fluorescence response to determine quality. Instead, GIA uses the fluorescent response as an identifying feature that helps distinguish different gems. The GIA grading report marks the intensity of the diamond's fluorescent reaction as follows:
None: No glow at all under UV light.
Faint: Glows faintly under UV light.
Medium: Glows under UV light.
Strong and Very Strong: Intense luminescence is clearly visible under UV light.
How diamonds use diamond fluorescence?
1,Higher grade, lower price.
Gemologists use color (one of the 4Cs) to help determine the quality of a diamond. Chromatographically more valuable are colorless diamonds marked D-F. Discounts are not uncommon when diamonds in the D-F color range have strong to very strong fluorescence responses. This happens because many people automatically assume that a high level of fluorescence response means the diamond will have a cloudy or greasy appearance. Although this effect is rare, such negative associations can reduce a diamond's perceived value.
2,Improve perceived color
nterestingly, in the H-K color range, the fluorescent reaction can improve the color of the diamond. Diamonds in this color range typically contain a yellowish hue, a combination that can make them appear whiter when offset by moderate or intense blue fluorescence.
Us and GIA
The loose diamonds we sell are analyzed and graded by GIA, the most accurate and authoritative laboratory in the diamond industry. Therefore, in light of the controversy surrounding this feature, we asked GIA for advice on diamond fluorescence reactions:
“The GIA study showed that, for the vast majority of diamonds, the intensity of the fluorescence response had no significant effect on appearance. The GIA fluorescence response study found that the average person could not distinguish between diamonds with fluorescence and diamonds without fluorescence. In many In some cases, observers prefer the appearance of diamonds with moderate to intense fluorescence. In rare cases, some diamonds with intense fluorescence may appear cloudy or oily; of the fluorescence diamonds submitted to GIA, less than 0.2 % exhibited this effect."