You may have heard about diamonds that Fluoresce under strong ultra violet light or diamonds that glow or appear opaque when at a night club / dance.
The fluorescence in a diamond is in fact very rare and sometimes considered as an inclusion by the purist although some may consider it, due to its rarity even more valuable.
The diamond fluorescence comes in varying degrees of colours although it tends to be blue in colour and in some even rarer cases yellow.
Despite this the fluorescence can improve the colour of the diamond by making them appear whiter or closer to colourless.
Fluorescence in a grades D – F can sometimes make the diamond appear opaque and poorly polished and these negative attributes obviously outweighing any positives even with distinct or strong fluorescence.
Diamond fluorescence is generally considered acceptable in diamond colour grades G to J as it improves the colouring and unseen unless looked at in strong ultra violet light (not an everyday occurrence).
Fluorescence in grades K to M can increase the potential of the diamond as these diamonds already have a faint yellow colour so the blue fluorescence counter-balances the yellow colour and makes the diamond appear whiter.
When a diamond is fully certificated by an independent laboratory the level of fluorescence is described on the certification report as ‘None’, ‘Faint’, ‘Slight’, ‘Medium or Moderate’, ‘Distinct’, ‘Strong’ and ‘Extreme’.