Diamond Fluorescence Buying Guide

If your diamond is H, I, or J color, then look for a diamond with medium blue fluorescence, it can make your stone look slightly whiter. If not, your stone will still look great without it.

If you are buying a diamond with a G or higher color, then find a diamond with either no fluorescence or faint fluorescence. Otherwise, consider a diamond with an I or J color stone to get the best value. These are general guidelines and not every case may fit into these.

Diamond Fluorescence

Fluorescence in diamonds refers to how a diamond responds when subjected to ultra-violet light. Ultra-violet light is what makes your whites look whiter, your teeth bright white, and your black light posters glow.

Some diamonds, when they are exposed to ultra-violet light and other lighting conditions, glow different colors. 99% of the time, the glow is blue, but on rare occasions, the diamonds can glow white, yellow, green, or even red in color. The story, however, doesn't end here.

Fluorescence Guide

Fluorescence guide.

Strong Blue Fluorescence

If the diamond only glows when exposed to ultra-violet light, then it should naturally only matter if you are someone who spends their days in dark rooms with black light lamps. But the fact is, most diamonds exhibiting Strong blue fluorescence appear slightly to severely hazy in regular lighting conditions. In our Diamond Fluorescence guide it mentions about a GIA study claiming that even strong blue fluorescence is almost always entirely imperceptible to the average diamond consumer.

Fluorescence in reference to diamonds still remains to be a widely misunderstood concept. When we talk about the fluorescence of a diamond, we are referring to the glow it has when it is exposed to ultra-violet light, and when it exhibits a blue color it appears higher in color than its true body color.

Diamond Fluorescence Color Grades

Looking at a diamond color chart, you will find that the GIA will grade the colors of the diamonds on a scale ranging from D through Z. D refers to the colorless diamonds, while Z diamonds exhibit a slight yellowish hue. All diamonds are also considered to contain varying degrees of some kind of color and are then each graded on a different color scale.

Diamonds graded at D are often absolutely colorless and they fall into the highest color grade possible and are also extremely rare. E-F color grades are for colorless diamonds that may contain minimal traces of color that can only be detected by a gemologist. They are also considered rare diamonds.

G-H on the color grade scale refers to near colorless diamonds in which the color may be harder to detect when they are not compared next to other diamonds of higher grades. However, they come at a more affordable price and are an excellent value.

I-J on the color grade scale is set aside for diamonds that have a warmer tone to them but are also considered near colorless.

Finally, K-Z on the color grade scale are diamonds with a noticeable color and are not carried by many retailers.

Reflection, Refraction & Dispersion

Diamonds will almost always get their brilliance from three different factors. These factors include reflection, refraction, and dispersion. When light hits a diamond, we are referring to reflection when that light is bounced back after hitting the diamond. The bouncing of light in this manner is what contributes to the shine of the diamond.

When light is reflected, it is typically only a small fraction of the light that bounces, the rest of the light will travel right through the diamond. Refraction is when the light is fractured or gets scattered as the light begins to travel through the diamond and this is where you will see the diamond's sparkle.

Dispersion occurs when the light first enters through the top of the diamond and then angles itself inside the diamond before it is then aimed back up and through the surface which then creates an almost rainbow-like effect that further contributes to how much the diamond will shine. Refraction and dispersion are also accountable for creating natural light and darker areas in the refracted light. The refraction and dispersion are invaluable when it comes to the overall brilliance of the diamond. The darker areas will become magnified, and there will be contrast. It is this contrast that allows the diamonds to shine as they do.

To sum it up, without reflection, refraction, and dispersion, diamonds would lose their shine and sparkle, and the brilliant shine is what many people are looking for when they choose a diamond ring.

High Fluorescence

Strong/Very strong blue fluorescent diamonds usually appear hazy, medium blue fluorescent diamonds rarely appear hazy and slight/faint blue fluorescent diamonds never appear hazy.

If the diamonds you are looking at have a strong or very strong blue fluorescence, then they will most likely appear hazy, oily, or cloudy and this will also cause the diamonds to appear less transparent. When comparing diamonds back to back, you will definitely see a difference between a diamond with strong fluorescence and one with little or none. It is also important to note that this extreme level of haziness for a fluorescent diamond is also not typical and is not as common as you may think when you are discussing diamonds that are H and lower.

Fluorescence On Color

Some studies done on fluorescence do make one claim that is correct. Fluorescence will usually improve the appearance of color in the diamond. As mentioned above, if you are buying a diamond with a color H or lower, seek out a diamond with medium blue fluorescence.

We are hesitant to suggest looking for a diamond with strong blue fluorescence since even lower colors can occasionally look milky and hazy when they have strong blue fluorescence. But the lower you go in color grades, the less likely it will be milky.

A medium blue fluorescent diamond color can even help counteract any yellowish tint the diamonds may have and can make them appear much whiter. In effect, this will make the diamond color and appearance an entire color grade higher.

Fluorescence can make the diamond shine and sparkle more than a diamond that lacks fluorescent properties.

Fluorescence Hesitations

We are also hesitant to suggest medium blue fluorescence when purchasing a diamond with very high color (G or better) since on rare occasions even a medium blue fluorescent diamond can exhibit milkiness or haziness when the color is exceptionally high.

If, of course, you are buying a diamond in person and not online, then it's in your best interest to specifically ask for a diamond with strong blue fluorescence.

It will be more affordable, and since you are there in person, you can see for yourself whether or not the diamond exhibits haziness or milkiness. Make sure to ask to see the diamond in a variety of different lighting settings, if possible.

Buying In Person Vs. Online

If you're considering buying in person, despite the savings you might gain by buying a strong blue fluorescent diamond, it will certainly still be cheaper for you to buy your diamond online and purchase either a medium or lower fluorescence.

Unfortunately, however, reputable jewellers with their advanced photography, cannot show you how the diamond will look face-up in direct sunlight. If possible, it is always better to try and see the diamonds in person so you can get a better outlook on their overall appearance in a different light source.

If you cannot look at the diamonds in person, be sure to check with the jeweller about their return policy, just in case. Remember, it is possible to purchase high quality fluorescent diamonds that boast of the brilliance and shine you are looking for without having to spend a fortune in the process or sacrificing on the overall quality of the diamonds.

Expert Tips

  1. It is up to your own tastes to determine if the fluorescence of the diamond is good or bad.

  2. Fluorescence can often improve the color of the diamond.

  3. Strong blue fluorescence does not necessarily mean there will be a negative effect on the diamond's overall color and appearance.

  4. Faint fluorescence of a diamond can actually save you money without having to miss out on brilliance.

  5. When shopping for fluorescent diamonds, always check into the retailer's return policy, just in case.

  6. Buy fluorescent diamonds from a reputable retailer to ensure they're high quality.

  7. When shopping, it is okay to ask to see the diamonds under UV and normal lighting, as well as inquire about how it may look when exposed to daylight.