Diamond Fluorescence

Fluorescence, the effect ultraviolet (UV) 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, pink, orange, and red. 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

Faint, Slight

Weak fluorescence, not a significant influence on color (barely perceptible)

Medium

Average fluorescence, small influence

Strong, Extremely Strong

Strong influence, substantial color influence

The Fluorescence Effect

Fluorescence can enhance or detract from the beauty of a diamond. The bluish tint can improve a lower-color diamond (J-M color rated) by cancelling out the faint yellow, resulting in a colorless appearance. However, in a very high-color diamond (D-F color rated), fluorescence may have the opposite effect.

In a small number of diamonds, the presence of strong fluorescence creates a hazy, milky, oily, or cloudy appearance. For this reason, very fluorescent diamonds can be valued lower than similar diamonds with fluorescent ratings of "None," "Faint," or "Medium." If you have selected a diamond with "Strong" or "Very Strong" fluorescence, please contact a Brilliance diamond and jewelry expert to have it visually inspected before purchasing.