Diamond Education
What is Fluorescence?
Fluorescence is the visible light some diamonds emit when they are exposed to invisible ultraviolet (UV) rays. On a GIA diamond grading report, fluorescence refers to the strength, or intensity, of the diamond’s reaction to long-wave UV, which is an essential component of daylight. The light emitted lasts as long as the diamond is exposed to the ultraviolet source. The majority of diamonds with medium blue, string blue or very strong blue fluorescence appear cloudy and milky. Because of this, these diamonds sell for 25 to 35 percent less than similar diamonds with faint or no fluorescence.
