By Gary A.
Edited by Brian M.
Published Jul 18, 2022
Edited on Dec 18, 2024
While diamond fluorescence may seem like a harmless feature, it can often diminish the overall clarity and brilliance, making it essential to carefully weigh its impact before making a choice.
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Before we dive deeper into the specifics, here are some practical tips to help guide your decision-making process:
Understanding Fluorescence Impact on Color Fluorescence in a diamond can affect its appearance, especially in terms of color. When buying an engagement ring, it’s crucial to understand how fluorescence interacts with the diamond’s color.
Assessing Fluorescence Aesthetics
Beyond the technical aspects, the aesthetics of fluorescence can be subjective and should be considered based on personal preference. We recommend avoiding Strong and Very Strong Fluorescence in diamonds.
Practical Considerations
Finally, some practical aspects can guide your decision when considering fluorescence in your diamond engagement ring.
Now that youâve got these practical tips, use Jeweler AI below to find the perfect engagement ring that suits your style and budget:
Odds are that, by now, youâve done at least some of the required reading on the Four Cs of Diamonds. At the very least, youâre probably aware of the fact that a diamondâs quality is determined according to cut, color, clarity, and carat weight and that these categories represent the most pressing things for any shopper to consider before committing to a diamond.
Still, thereâs a little more to it than that. Diamond fluorescence represents yet another important consideration to add to your radar as you begin your search for the perfect diamond.
Fluorescence can be a great thing for your diamond. It can also be a bad thing, and significantly lower the visual appeal and value of your diamond. Confused? Donât panic â knowing the basics will ensure you donât make any mistakes.
Some diamonds fluoresce, meaning that they glow under black light. This glow is typically blue, although the glow varies from faint to bright â and, in more severe cases, can be to the detriment of the diamondâs appearance.
Fluorescence is not just a phenomenon reserved for white shirts under the disco black lights â itâs also a pretty common occurrence in nature. Many minerals, from opal to fluorite itself, will glow under UV lights â diamond included.
The majority of diamonds glow blue under UV light â and not to the extent that the appearance of the diamond is impacted under usual lighting conditions or daylight. Other diamonds will fluoresce different colors, such as red or green, but this is very rare.
Some diamonds, however, are so fluorescent that they can appear cloudy under direct sunlight. Their value can be lowered alarmingly, particularly if they have a high-color grade.
No, it is thought that just under a third of diamonds mined from the earth fluoresce.
This is yet another thing that serves to demonstrate quite how unique and fascinating every diamond is. Around 70% of diamonds have no fluorescence at all, meaning that, in many cases, this subject doesnât impact a shopperâs decision at all.
Still, itâs very important to know that fluorescence can exist in a diamond, and that itâs not always âno big dealâ.
Very minor fluorescence wonât be noticeable to the naked eye, but strong fluorescence means that the diamond will glow bright blue under black light, and that it is likely to appear sort of âmilkyâ under normal lighting conditions.
It also means that its value could be up to 70% lower than it would be for a similar diamond with faint or no fluorescence since the diamondâs appearance is permanently affected by its fluorescence.
The GIAâs grades for fluorescence are: None, Faint, medium, Strong, and Very Strong.
While it is not talked about as much as the Four Cs, a diamondâs fluorescence is checked and recorded within its GIA report. Since it impacts a relatively small number of diamonds â and impacts the value of even fewer than that â the topic is not considered to be as pressing as other natural or human-made features.
Still, shoppers should be wary of any diamond that strays beyond the range of None, Faint or Medium. Strong and Very Strong Fluorescence is considered pretty undesirable, for a few key reasonsâ¦
Thereâs no âideal spotâ for fluorescence, as it can negatively impact diamonds with a higher color grade much more than it impacts diamonds with a slightly lower-color grade.
Still, thatâs not to say you have to pass up a beautiful diamond simply because of its grade.
Faint Fluorescence in Diamond
This is normal and nothing to worry about. Faint fluorescence wonât cause any sort of a blue cast in your diamond, and it wonât make it appear cloudy, either.
Medium Fluorescence in Diamond
A medium grade should be avoided in diamonds with a very high-color grade, as any cloudiness can be more noticeable in these diamonds. In some diamonds, this level of fluorescence is thought to benefit the appearance of the stone.
Medium fluorescence still produces plenty of beautiful and wearable diamonds, but this category should be regarded as the upper limit and treated with caution as a result.
In diamonds with lower-color grades â particularly those in the lower end of the Near-Colorless category on the GIAâs Color Scale â some jewelers feel that a mild fluorescence can improve color, and counteract any slight tint the diamond might have.
Strong Blue Fluorescence in Diamond
This level of fluorescence will interfere with a diamondâs transparency. However, some rare diamonds can fluoresce blue without looking milky â and, for collectors, they hold a very unique sort of appeal.
When it comes to diamonds with cloudy/milky appearances, then strong fluorescence is a bad thing. Why? Because the trouble with a cloudy diamond is, unless youâre an expert who understands the different types of diamond inclusions, it wonât look like a real diamond at all. Even people who have never seen diamond âin the fleshâ before still know what theyâre supposed to look like bright, vibrant, brilliant, and fiery and, put simply, more beautiful and dazzling than any other gemstone out there. A diamond that is so cloudy and dull that it appears to have had the life sucked out of it is going to appear to most people like a cheap imitation.
For instance, diamond simulants like cubic zirconia (CZ) can be cut and polished to look as much like diamond as possible, but they still canât live up to expectations. CZ scratches easily and, over time, takes on a cloudy appearance â so you can imagine why a cloudy diamond fails to impress experts and non-experts alike.
Put simply, no one wants a cloudy diamond. While theyâre pretty interesting things to look at and study under a microscope, they simply donât live up to the expectations most of us hold for engagement rings and will fall short on one of the most important traits a diamond has: sparkle. Youâre going to wind up paying far more than you should for a diamond that looks like itâs worth a fraction of its price tag.
As we mentioned above, however, a small number of diamonds have strong fluorescence, but no milkiness. In these instances, the strong fluorescence can help to make the diamond appear to have a better color than it really does when the diamond is exposed to the light. Some people (mainly collectors) enjoy tracking these diamonds down for their pretty unique properties and strong blue glow, which is visible when the diamond is exposed to UV light.
In some cases, slight fluorescence can counteract the presence of a minor amount of visible color in a diamond.
The trouble for us is that looking for a diamond with the âright amountâ of fluorescence to improve its color is not an exact science. It is far easier and more cost-effective to look at diamonds with a Near-Colorless grade of G, H, I, or J. There are plenty of options that show no discernible color or fluorescence. For that reason, the overwhelming majority of buyers looking for a diamond for their engagement ring would prefer to stay safely within the lower grades (None, Faint, and Medium), ensuring little to no fluorescence and a clear, bright, sparkling diamond.
There are flaws worth investing in â inclusions and color that are not visible to the naked eye â but we canât see the value in investing in a diamond that is flawed in this way. Itâll take you longer, and put you at more risk of a dud.
The better approach would be to look at diamonds with a slightly lower (though still eye clean) clarity grade, such as VS2 or SI1, or a slightly smaller diamond â or, perhaps, a diamond shape thatâs good at concealing slight color (more on that below) so that you can afford to find a diamond that appears colorless.
While an interesting subject, fluorescence is generally seen as a negative trait in any diamond â and particularly among those looking to create an engagement ring â so donât commit yourself to a potentially long and frustrating search for a diamond that has both color and fluorescence, but which appears colorless.
Fluorescence itself isnât particularly rare, but some diamonds feature a very rare and beautiful form of fluorescence that gives them a distinctive blue color.
You musnât get these diamonds mixed up with fancy blue color diamonds. These diamonds are made blue by the presence of trace amounts of the chemical boron, which âcontaminatedâ the diamond millions of years ago when it was still forming underground. These diamonds appear in varying shades of blue, from pale and icy to a deep, rich shade reminiscent of sapphire (though still offering the diamondâs unparalleled brilliance and fire). Their color is always visible,
Strong blue fluorescence is not always visible within the diamond â it âcomes outâ when the diamond is exposed to UV light, such as a backlight. Under normal conditions, these diamonds will look pretty normal and unassuming.
Their popularity among certain collectors has made them marketable. The 5th generation diamond cutter Brian Gavin has turned strong blue fluorescence into a selling point. His collection âBlueâ comprises diamonds with strong fluorescence, but an AGS light performance grade of 0 (ideal).
Anywhere from âNoneâ to âMediumâ on the GIA Scale, although fluorescence â like any trait a diamond holds â will look different on every stone.
If youâre sticking firmly to the higher grades for color then, ideally, your diamond would have no fluorescence â but, as we said before, donât let that deter you from an otherwise beautiful diamond. Provided you stick within this range, then the most important thing is what you think of the diamond â and, as we always say, whether or not itâs eye clean.
Chances are you donât want to give your future bride a blue-tinted diamond. While theyâre pretty cool to look at, theyâll never replace clear, sparkling diamonds as the ultimate token to present when you propose.
Still, you donât need to beat yourself up if your heart is pulling you toward a diamond that has a certain amount of fluorescence. Weigh up the pros and (potential) cons, and let your instincts guide you the rest of the way.
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