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Adrian Lee

Diamond Fluorescence

Of all the diamond qualities, fluorescence is probably the most polarised in opinion and the most misunderstood.  Fluorescence is generally a fairly minor aspect of diamond grading but does play an important part in the price and saleability when selecting a diamond.

When diamonds are exposed to UV light diamonds there is a natural occurrence where they will emit a fluorescent light.  This fluorescence occurs when there are unbonded free electrons within the carbon atomic structure that vibrate when exposed to UV light, the more free electrons available the stronger the fluorescence.   A faint or medium fluorescence will never impact the appearance of a diamond in any circumstance but will help to reduce the cost of a diamond.  In all but a very few exceptions, a diamond’s fluorescence will not negatively impact the visual appearance of a diamond and in lower colour grade diamonds is often said to sometimes improve the whiteness of the diamond.  Of the less than 1% of diamonds that are visually affected by fluorescence these are usually D-F coloured diamonds with a strong or very strong grade and will show a slight milkiness to the diamond.  Because of this it is generally best to avoid a diamond with a strong grade but as long as the stone has been inspected a strong grade is not a bad choice when it is needed to reduce the cost of the diamond.

How Common is Fluorescence?

Around 35% of all diamonds will have some level of fluorescence that will be graded as faint or above and those that show a readable amount under a UV light will rarely ever have an actual visual impact on the diamond.  To see a diamond’s fluorescence it needs to be viewed under only UV light, it will show as a pale blue outline to a full body glow but can sometimes also be green,orange or yellow.  Because fluorescence is blue in the lower grade diamonds coloured “I” and below where there is a tint of yellow, fluorescence can actually help make the diamond look whiter as the blue light will counteract the yellow in the diamond.  Diamonds coloured G and H are quite fine to have a medium or strong fluorescence as it may still help make the diamond appear a little whiter with a bit of a “pop” to the colour with very little chance of having a negative impact.  Any diamond with a faint grade is almost the same as having a nil grade but will just be slightly cheaper.

What Impact does Fluorescence have?

Fluorescence is a minor grading trait that has little impact on a diamond’s appearance but more to do with the conceived value and perfection of a diamond. It is also an effective way of helping to identify a gem as a diamond.  In natural light there is UV light, which will cause the diamond to fluoresce but is masked because of the presence of the other wavelengths of light.  Only in highly transparent D-F coloured diamonds with a very high fluorescence when viewed in full sunlight can a discerning eye can pick up that the diamond will exhibit a slight milky or hazy appearance and in very rare occasions this will be at a level that causes a negative impact.

So What does Fluorescence Mean to My Purchase?

Although fluorescence has very little impact on the appearance of a diamond except in the few rare circumstances it does play a significant part in the price of a diamond and the general acceptability of the diamond for sale.  Currently a perfect diamond is considered to have a nil fluorescence grade and with around 65% of diamonds having a negligible grading this is generally the standard when purchasing a diamond.  However for buyers who are a little less concerned about the paper value of a diamond having a diamond with some fluorescence can provide a better value diamond while having the least impact on the appearance.  To improve the value of a diamond by adding fluorescence, while still ensuring there will absolutely be no issues we recommend that for any colour grade a medium or faint is preferable and up to a strong grade for colours that are below “G” and to avoid a strong or very strong in D-F colours unless it is totally necessary.

Search Wholesale Diamond Prices Online

Once you have decided on the type of diamond you would like to buy, our wholesale diamond search tool is a great place to start looking for quality loose diamonds in your budget.

The online diamond search inventory is an international list of available loose certified diamonds that will give you a great guide to the wholesale price of different quality diamonds to help make your selection.

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