In the diamond industry, the existence of fluorescence in a diamond , has caused many debates and has, in many instances, influenced the pricing of diamonds. Fluorescence, the effect ultraviolet light has on a diamond, is an important consideration when selecting a diamond. When UV light strikes a diamond with fluorescent properties, the stone emits a glow that is usually blue, but can also reflect shades of green, yellow, white. The sources of fluorescence, boron and nitrogen, are the same mineral properties that lend color to a diamond.
Fluorescence can occur in different intensities. Gemological laboratories rate the fluorescence of each diamond on a scale from “None” to “Very Strong”.
None, Nil, Negligible
No fluorescence, no influence on color
Weak fluorescence, not a significant influence on color (barely perceptible)
Average fluorescence, small influence
Strong, Extremely Strong
Strong influence, substantial color influence