Diamond Fluorescence



An Effect ultraviolet (uv)
light has on a diamond

when uv light strikes diamonds with fluorescent properties, the stone emits a glow that is usually blue.

however, it can also reflect shades of green, yellow, white, pink, orange and red.


Fluorescence can occur in different intensities. gemological laboratories rate the fluorescence of each diamond on a scale of none, to Very Strong.


The presence of fluorenscence can enhance the visual appeal of a diamond with a lower colour reting in the J through M range.

Fluorenscence also helps to cancel out any faint yellow visible in a stone, resulting in a colorless appearance.


No fluorescence,
no colour influence

none, nil, negligible

Week Fluorescence,
insignificant colour influence

faint, slight

Average fluorescence,
small colour influence


Strong fluorescence,
substantional colour influence

strong, extremely strong


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.

how does fluorescence affect pricing?

Historically, strongly fluorescent diamonds have been marked down in price next to their non-fluorescent counterparts.

Typically, higher color (D-H) non-fluorescent diamonds will sell for 10-30% more than similar stones that exhibited very strong blue fluorescence.

However, lower color (I-N) diamonds with very strong fluorescence were priced 5% higher than similar non fluorescence stones. this could be due to the perception that blue fluorescence can mask the undesirable yellow tones found in some stones.