Educational Home > Diamond Education > The Anatomy of a Diamond > Fluorescence


When diamonds display a visible glow when exposed to ultraviolet (UV) light this is referred to as its fluorescence.
Nearly all diamonds will have some degree of fluorescence. For many lighting conditions, a diamond's fluorescence
will not be visible to the naked eye. However, it may release a soft colored glow if held under an ultraviolet lamp.
Fluorescence is a naturally occurring phenomenon created from the mineral properties boron and nitrogen.
It can appear in many minerals and gems.

Diamond fluorescence occurs in varying intensities and colors. Gemological laboratories rate the fluorescence
of each diamond on a scale ranging from "None" to "Very Strong". Fluorescence is categorized as 'None' when
there is no visible reaction under ultraviolet light. It will be categorized as 'Faint', 'Medium', 'Strong', or 'Very Strong'
depending on how much glow is observed. The color range of the glow varies from standard blue to shades
of green, white, pink, yellow, red or orange. See the below chart for more details.

None, Nil, Negligible No fluorescence, no influence on color Anjolee Diamonds
Faint, Slight Weak fluorescence, not a significant influence on color (barely perceptible) Not carried by Anjolee
Medium Average fluorescence, small influence Not carried by Anjolee
Strong, Very Strong Strong influence, substantial color influence Not carried by Anjolee