Fluorescence in a diamond refers to the visible glow that occurs when the diamond is exposed to ultraviolet (UV) light. This glow is created by the natural presence of minerals such as boron and nitrogen within the diamond. Fluorescence can be found in many minerals and gems.
Nearly all diamonds have some degree of fluorescence, although it may not be visible to the naked eye under certain lighting conditions. An ultraviolet lamp can be used to reveal a soft-colored, fluorescent glow in the diamond.
Diamond fluorescence occurs in different intensities and colors. Gemological laboratories assess the fluorescence of each diamond on a scale that ranges from “None” to “Very Strong.” When there is no visible reaction under UV light, the diamond’s fluorescence is categorized as “None.” If there is a visible glow, it will be classified as “Faint,” “Medium,” “Strong,” or “Very Strong” based on the intensity of the glow. The color of the fluorescence can range from blue to shades of green, white, pink, yellow, red, or orange.
Diamonds with no fluorescence exhibit no discernible fluorescence under UV light, making it negligible in terms of its influence on the diamond’s color.
Faint / Slight Fluorescence
Diamonds with faint or slight fluorescence emit a weak glow under UV light, which has minimal impact on the diamond’s color and is barely noticeable to the naked eye.
Diamonds with medium fluorescence display an average level of fluorescence when exposed to UV light, resulting in a slight influence on the diamond’s color, but usually not visible to the naked eye.
Diamonds with strong fluorescence exhibit a pronounced fluorescence effect under UV light, which can have a noticeable impact on the diamond’s color. This fluorescence may result in a slight hue or overtone, which can be either preferred or considered less desirable depending on personal taste and the specific diamond’s appearance.
Very Strong Fluorescence
Diamonds with extremely strong fluorescence display a highly pronounced fluorescence when exposed to UV light, significantly impacting the diamond’s color. This level of fluorescence can result in a more pronounced coloration, potentially leading to a noticeable tint or overtone, which may or may not be desirable depending on personal preferences and the overall appearance of the diamond.