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What is diamond fluorescence?
Most salespeople don’t like to talk about fluorescence because it can be complicated. Often, they don’t know how to explain it. This happens more than you realize.
But, it is very important that YOU understand what it is.
So, here’s the scoop on fluorescence…
Fluorescence occurs when tiny traces of other elements, such as boron or nitrogen, sneak into a diamond’s crystal structure as it forms deep underground. When exposed to ultraviolet light, these molecules get excited and emit visible light.
A little fluorescence is fine, but more than that can make your diamond look hazy or milky in sunlight and under fluorescent lighting.
How is it possible to tell if a diamond is fluorescent?
When you look at a diamond grading certificate, you will see fluorescence noted as none, faint, medium, strong, or very strong.
These different levels refer to the strength or intensity of a diamond’s reaction with ultraviolet light.
Diamond Fluorescence
on a diamond grading certificate
NONE or FAINT
A diamond never looks hazy or milky
MEDIUM
A diamond rarely looks hazy or milky
STRONG OR VERY STRONG
A diamond usually looks hazy or milky
Approximately 25-35% of all diamonds exhibit some type of fluorescence.
The vast majority of diamonds that are fluorescent have a visible (sometimes slight)
shade of blue under sunlight or fluorescent lighting.
Follow these guidelines…
D,E,F,G color
The most desirable fluorescence for D,E,F,G color is none or faint.
DO NOT consider fluorescence grades of medium, strong, and very strong for this color range.
Fluorescence tends to lower the value of diamonds that score high in both clarity and color. For example, D to G color diamonds with high clarity grades often see price drops of 3 to 15 percent if the fluorescence is very strong.
H,I,J,K color
The most desirable fluorescence for H,I,J,K color is none, faint, or medium.
Diamonds in the J and K color range with medium fluorescence may appear slightly whiter under ultraviolet light.
Please note that I am advising you NOT to purchase diamonds with strong and very strong levels of fluorescence.
These intense levels of fluorescence may make your diamond appear slightly to severely hazy or milky when in the sun or under fluorescent lighting.
Price Break
If you are still considering a diamond with strong or very strong fluorescence, be sure you see it in person under different types of lighting. This is an absolute must, so you can make a decision if the higher degree of fluorescence matters to you.
Diamonds with a high degree of fluorescence should NEVER be purchased online. You need to see it in person.
Here are good questions to ask:
Can I see the diamond under a UV lamp?
Will this diamond look cloudy in the sun?
Can we compare it to a diamond with little or no fluorescence?
Only consider making a purchase if you have viewed the diamond under different types of lighting.
A price break of 5% to 15%, or more is standard for diamonds that have strong or very strong fluorescence.
Check the Grading Certificate
Always review the diamond grading certificate before buying. Pay close attention to the
fluorescence rating. Avoid diamonds with strong or very strong fluorescence.
Some diamonds with high fluorescence may seem like a bargain. Their lower price often hides
the reason—they can look cloudy or milky in sunlight or under bright indoor lights.
Choosing a diamond with faint or no fluorescence helps you get a diamond
that stays clear and bright in any lighting.
