Diamond Fluorescence

Fluorescence

Fluorescence is only detectable under strong ultra violet light and comes in varying degrees of colour. The fluorescence of diamonds tends to be a blue colour and in rare cases yellow (this is more commonly found in coloured stones). Fluorescence in diamonds is very rare, whilst cut, clarity, carat and scarcity of colour all increase the price of a diamond, but fluorescence actually decreases the price of the diamond.

Fluorescence in a diamond can be regarded as an inclusion and this reduces the cost of the diamond. Despite this, fluorescence in diamonds can make them appear whiter and closer to colourless. Blue fluorescent colouring can actually improve the colour of a diamond by a grade or two but at a lower cost.

Diamond Fluorescence - Negative and Positive

Diamond fluorescence is generally considered fine in diamonds from G to J as it improves the colouring but reduces the cost. Fluorescence in a diamonds from D - F can make the diamond appear opaque and poorly polished and these negative attributes outweigh positive even with distinct or strong fluorescence that is extremely rare.

Fluorescence in diamonds from K to M can increase the price of the diamond as these diamonds have a faint yellow colour the blue fluorescence counter-balances the yellow colour and makes the diamond appear whiter. The level of fluorescence in a diamond should be reported on the diamond certification. Levels of fluorescence in a diamond is described on the diamond certification report as 'None', 'Faint', 'Slight', 'Medium or Moderate', 'Distinct', 'Strong' and 'Extreme'.