The truth about FLUORESCENCE

It is a total misconception and usual misinformation that fluorescence, especially up to what, on a grading report would be considered as even 'strong', have any influence at all on the clarity or the light refractive qualities of a diamond.

After the strong classification one enters the realm of the 'intense' levels of fluorescence, these will, in the very worst of cases, in the form of an opaque 'cloud' have an effect on the clarity and brilliance of the diamond and will be qualified as such on the grading report.

It is quite the contrary in fact to this misplaced information that fluorescence in a diamond is undesirable.

Before certificates came about, in Europe, we used to call the best possible colour as 'blue white' colour. This equates in fact to a 'D' colour with strong fluorescence, a most desirable combination as it gave the diamond that very special bluish 'ice white' feel that only these types can give as opposed to the 'ordinary' 'D' colour.

Now if you thought that a 'D' colour was rare, then a 'blue white' is far rarer.

For every 20 'nil' fluorescent 'D' coloured diamonds you may possibly have 1 strong fluorescent one if that. This is the main reason why dealers talked them down as once certificates became popular, they were so rare that dealers would miss out on clients requiring the best there was, possibly having to wait many weeks until one came around. Nobody, therefore, had an advantage in 'pushing' them so they became less desirable, due to market 'hype'.

That's the true picture so if you talk about 'slight' or 'medium' or even 'strong' fluorescence in a diamond the clarity and brilliance (sparkle) will most certainly not be affected in any way. Fluorescence can be yellow, green and tints of these not only blue.

If someone has made you believe the contrary have him/her get in touch with us and we will put them back on the right path.

In fact with diamonds in colours below the 'I' colour, fluorescence has a very beneficial influence on the diamond as it makes the diamond look whiter from the top.

In everyday wear, especially under sunny conditions, say a strong fluorescent 'K' colour will look as white as a 'G' or even as an 'F' as the fluorescence will add a blue (whiter) tint to the diamond. These will sell better and be more desirable and more expensive in the process.

This is proof that fluorescence does not affect clarity or sparkle in anyway as long as it is not 'overly intense' of course.

Always happy to answer any further questions on this subject.

George Zaidmann
Certified Gemmologist
Member of the Antwerp Diamond Bourse since 1972