Is Strong Blue Fluorescence In A Diamond Bad?

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Fluorescence in diamonds can be strong or faint blue. But although the faint blue Fluorescence doesn’t change or affect the color and clarity qualities of the diamonds much, strong blue and the very strong blue fluorescence will interact with the existing yellow hue in most diamonds in the lower color grades, resulting in a significant change in the diamonds, a milky appearance, low brilliance, and a reduction in the value of the diamonds.

So in this regard, a strong blue fluorescence might not be the best thing for diamonds.

Generally, the strong blue fluorescence will have a negligible effect on the appearance of the diamonds when you look at the stone from the top down, especially for the diamonds on the colorless and the near-colorless color grade ranges, that is, color grades D to J.

But there are rare instances where the diamond color is affected strongly by the strong blue intensity of the fluorescence.


What is strong blue fluorescence in a diamond?

Is Strong Blue Fluorescence In A Diamond Bad

Before we look at the meaning of different fluorescence intensities, let’s first define diamond fluorescence. Essentially, fluorescence can be defined as the glow seen off diamonds when the stone is exposed to UV light, including black light and sunlight.

Up to 30 or 35% of diamonds will fluoresce or glow under UV light, and as much as 99% of the time, they give off a blue light. There are rare instances, however, when the diamonds give off a yellow, white, green, orange, or red color.

That said, the GIA classifies the diamond’s fluorescence into 4 primary grades: None, Faint Fluorescence, Medium Fluorescence, Strong, and lastly, Very Strong Fluorescence.

Is Strong Blue Fluorescence In A Diamond Bad

The other thing you need to know about the fluorescence of diamonds is that there are instances when fluorescence will enhance the color features of the diamond. Still, on the high-grade diamonds, it lowers their quality.

And in many cases where the diamonds have a strong fluorescence, the diamond looks cloudy, hazy, or milky. While the haziness means a price drop, the diamonds you end up with are not always the best varieties for you.


What causes blue fluorescence in a diamond?

Is Strong Blue Fluorescence In A Diamond Bad

Fluorescence results from trace minerals in the crystalline carbon structure that forms diamonds. It occurs in the submicroscopic structures within the carbon crystals and the trace minerals that find themselves deep in the crystals.

The most rampant mineral or substance that contributes to fluorescence is nitrogen, although traces of boron also contribute to the fluorescence.

Note that these are naturally occurring substances in the diamonds during the natural crystallization process. The blue results from the interaction of the minerals in the diamonds with sunlight or dark, better known as UV light.


Diamond fluorescence strong vs. strong blue

Is Strong Blue Fluorescence In A Diamond Bad

The difference between the strong and the very strong blue fluorescence lies in the impact each level of fluorescence has on the diamonds when you look at the diamonds with your naked eyes.

The D -G grade diamonds are the ones that often have the high fluorescence that results from the interaction of colors (blue and the hints of yellow that occurs naturally when the diamond is exposed to UV light).

Unfortunately, the strong interaction of colors leads to counteractions that leave you with low-brilliant diamonds that appear milky white and hazy. With the diminished level of brilliance, the diamonds are not as valuable.

Note that this is different from the effects of fluorescence on the stones that already have a hint of color, like the I-grade diamonds and others below this grade. With such diamonds, fluorescence will make the diamonds look brighter.


Strong blue fluorescence diamond good or bad?

Is Strong Blue Fluorescence In A Diamond Bad

Theoretically, the strong blue fluorescence can be a good thing because when it happens to lower-grade diamonds with yellow inclusions, the diamonds develop a whiter shade, especially in well-lit areas.

But then the fluorescence effects are diminished when the distance from the light source increases. So, the diamond you buy might not look as good when you get home.

And in terms of the quality of the diamonds, the strong blue fluorescence might not be an entirely good thing. Also, as mentioned above, the value of the diamonds with a very strong fluorescence drops heavily, meaning that it’s not a good thing unless you’re shopping for the D-graded diamonds at a bargain.

Also, the blue-white diamonds look more milky white and may not sparkle as much, and as you may know, the cloudy or the milky diamonds are not valued as high as the bright white or transparent diamonds.

Is Strong Blue Fluorescence In A Diamond Bad

Because of the cloudiness problem with the strong and even the medium fluorescence diamonds, buyers are encouraged to avoid the diamonds that fall in the DEF color grades.

Note that the grades of the diamonds matter as well, with the bluish tint of the diamonds from strong fluorescence in the almost colorless diamonds in the J-M grades having an overall bright effect as the blue, cancels out that faint yellow hue in the diamonds, resulting in colorless and bright sparkling diamonds.

DEF diamond grades are diamonds whose quality is undesirable, and these diamonds carry very little value because the high fluorescence means the diamonds look hazy and milky.

Is Strong Blue Fluorescence In A Diamond Bad

Here, fluorescence is seen as a flaw, and the value of the diamond dips. So, if you are worried about the value of your diamond engagement ring, consider its fluorescence and the color grade; the higher the grade, say I-M, the higher the value of the diamonds, and this is the case because the diamonds will end up looking white and brighter than they are as the yellow undertones are canceled by the fluorescence, leaving you with brighter and higher-quality diamonds.



You can choose to buy the fluorescent diamonds or not, but it’s important to remember that ultimately, the color, cut, clarity, and the carat weight of the diamond carry more weight than the fluorescence.

For the best value for money, opt for the diamonds graded high for color and clarity properties. But for cheaper, albeit good quality diamonds, check out the fluorescent diamonds.

Don’t forget that the strong blue fluorescence can be good or bad depending on the color properties of the diamond.

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