Blue Nuance in Lab-Grown Diamonds: Is It a Bad Thing?

Last Updated on July 22, 2023 by Juli "Jewels" Church

Have you ever noticed a blue hue in your colorless lab created diamond engagement ring? You're not the only one.

There's a reason for this blue glow in lab diamonds and it doesn't have anything to do with diamond fluorescence. This optical effect is referred to as blue nuance in lab grown diamonds.  

Let's explore the following questions:

blue nuance in lab grown diamonds
  • Is blue nuance the same as fluorescence?
  • Is blue nuance noted on a lab diamond grading report?
  • Are lab diamonds with blue nuance cheaper?

What is Blue Nuance in Lab Diamonds?

Buying lab grown diamonds is all the rage right now, and it's not hard to see why. There's many benefits to buying a lab grown diamond over a natural diamond. There's also a lot of misconceptions and misunderstandings about man made diamond jewelry too.

Lab created diamonds are produced via two main processes: HPHT diamonds and CVD diamonds. HPHT diamonds can have a natural bluish hue called blue nuance. Sometimes the bluish hue may be perceived as a greenish hue.

It is similar to how colorless natural diamonds have a natural brown or yellow hue left there by nitrogen impurities. In the HPHT process, there can be excess boron impurities in the crystal structure during the growth process.

Type IIa vs Type IIb Lab Grown Diamonds

Alright, here's where it gets confusing if you're not a science person, or a chemist for that matter. So, if you don't know about how lab diamonds are made, you may want to check out that link first.

In the 1930s, diamond experts wanted to classify the diamond atomic structure based on their color and physical properties. All diamonds are pure carbon, but the diamond crystal lattice can change during the growth process. Diamonds are susceptible to boron nitrogen impurities. These impurities can replace atoms within the crystal structure.

When lab diamonds are grown using a diamond seed, trace elements of nitrogen and boron are introduced to the structure as the lab diamond forms.

It used to be that diamonds were separated in Type I and Type II. Now, there's Type Ia, Type Ib, Type IIa and Type IIb.

Type Ia- 95% of natural diamonds are Type Ia. These contain groups of nitrogen atoms within the crystal structure. Some Type Ia diamonds may also be called "cape diamonds" because they originate from Cape Province, South Africa.

Type Ib- These diamonds have no measurable amount of nitrogen or boron impurities. They are often a colorless icey white, but can still be gray, light brown, light pink, or light yellow. They are the most pure of all diamond types.

Type IIa- Instead of forming in clusters, nitrogen impurities are isolated atoms. The results produce a bright yellow hue. You will know these rare intensities as canary yellow diamonds. Canary diamonds aren't the exact same as all fancy yellow diamonds.

Fancy Yellow Diamond

Type IIb- These types of diamonds are responsible for blue and bluish gray diamonds. They are also known to conduct electricity as well. They have high amounts of boron. Diamonds with strong blue hues are very rare.

Fancy Blue Diamond .16ct over $50,000

How is Blue Nuance Different from Diamond Fluorescence?

Diamond fluorescence can be present in all types of diamonds whether they're mined diamonds or lab created diamonds. Fluorescence is when a diamond or gemstone glows blue under UV light, like direct sunlight. Fluorescent diamonds may have traces of boron, aluminum or nitrogen in its structure.


Fluorescence in colorless diamonds are noted on the diamond's grading report or diamond certificate. Not all diamonds have fluorescence, but many of them do. Diamonds may have Strong, Medium, Faint, or no fluorescence at all. If your lab diamond engagement ring has blue nuance, you won't see it written anywhere on its diamond certificate.

Blue nuance and fluorescence are both optical effects that have no impact on durability of your diamond, similar to the bow-tie effect with oval diamonds. A fluorescent or blue nuanced diamond still sparkles the same as any other diamond.

Understand that diamond fluorescence is a blue glow that happens when a diamond is under UV light. Mined or lab diamonds can have strong fluorescence, but only lab created diamonds that have been created with the HPHT process can have blue nuance. Blue-nuanced diamonds have a blue tint under any type of light. UV light has no bearing on these diamonds.

What's the Difference Between Blue Lab Diamonds and Lab Diamonds with Blue Nuance?

A diamond with a saturated blue hue is called a blue diamond. Blue diamonds are very rare fancy color diamonds. Lab diamonds with blue nuance aren't fancy blue diamonds. Fancy blue diamonds can be natural or lab-created.

The blue color in a blue diamond is also caused by boron impurities, just like blue nuance in lab diamonds. Blue hues in a blue diamonds vary in intensity and often have secondary hues. HPHT lab diamonds that exhibit blue nuance don't have secondary colors, nor do they have the saturation. Blue nuance is gives a diamond bluish undertones, not a blue color throughout.

Mined diamonds with fancy blue hues are rare and expensive, so you shouldn't worry about being sold something other than a blue nuance lab diamond.

Just remember, a diamond's grading report will always tell you if you have a lab diamond or a fancy colored diamond. Just always buy certified diamonds.

Colored Diamond Grading Report

Blue Nuance FAQs

Is Blue Nuance in a Lab Diamond Bad?

Just like fluorescence, blue nuance in lab diamonds is an optical effect. It doesn't have any bearing on the durability of your diamond, but it can have some implications.

Listen up.

Some HPHT lab diamonds that have a strong blue nuance may be graded as a lower color grade on grading reports. When diamonds are graded, they're graded upside down. The presence of color within the diamond as a whole determines its color grade. And since blue nuance in a lab diamond is present in any kind of lighting, the stronger colored ones get factored into the color grade.

The other thing is that some cheap diamond testers can cause HPHT diamonds with a strong blue nuance to fail as a real diamond, despite all lab diamonds being real diamonds. The boron impurities set off the tester causing a misread.

To be honest, diamond testers are very fickle, whether we're dealing with lab diamonds or natural diamonds. They can read wrong if they're pressed too hard or at an angle. I wouldn't rely on a diamond tester alone to make sure your diamond is real.

Do All Lab Grown Diamonds Have Blue Nuance?

You already know that CVD diamonds don't have blue nuance like HPHT diamonds. However, both lab diamond processes are susceptible to fluorescence and phosphorescence.

But even more than that, not all HPHT diamonds have blue nuance either. The HPHT diamond process is fully capable of producing colorless diamonds without faint blue hues. The blue nuance in HPHT diamonds aren't always strong blue either, they can be a very light blue tint too.

How Do I Know if My Lab Diamond Has a Blue Hue?

Brick and mortar jewelry stores have just started to introduce lab grown diamond engagement rings into their cases, as most of them have always focused on natural diamonds. However, many of those retail employees won't know anything about blue nuance. They probably won't let you inspect all of their lab diamonds either. Majority of lab grown diamond engagement rings at stores like Jared or Zales won't have certified lab diamonds either.

Buy a Certified Lab Diamond

It's so important to have a certified lab diamond. Any center diamond you buy should always be certified. Unfortunately, stores tend to have very few certified diamonds and if they do-they're overcharging for them.

But if you take your lab diamond search online, it can be confusing. Even with interactive 360˚ video, it can be hard for you to see which diamonds have blue nuance. Many online retailers have diamond filters for fluorescence, but not for blue nuance.

GCAL Lab Diamond Grading Report

Use 360˚ Viewers and HD Photos Online

If you're not good at detecting blue color in your lab diamond via video or HD pictures, some lab diamond grading reports will tell you if you have an HPHT diamond or a CVD diamond. Now figuring out if it has blue nuance or not, that's for you to determine.

Consult a Lab Diamond Expert

Distinguishing blue nuance online can be difficult, but most online retailers have diamond experts that can refer you to a diamond without any faint blue hue if you want. Make sure you purchase from a reliable online retailer with a good and easy return policy just in case blue nuance is not your thing.

Lab Diamonds Aren't All the Same

Even if a lab diamond has the same grades as another, there's still many things that could be different from them. Lab diamonds produced with the HPHT growth process can exhibit a light blue hue in your diamond. This hue can be seen in all type of light, making it different from typical diamond fluorescence.

Blue nuance in a lab diamond is a preference, not a dealbreaker. Some people are fond of the tint, while others avoid diamonds with tint. The same is true for fluorescence.

Most people look for diamonds are looking for colorless diamonds with no hue. Some lab diamonds that have had a blue nuance can be treated by removing boron. This causes the tint to become more gray than bluish.

You should always purchase your diamonds from a reliable online retailer accompanied with diamond certificates from reliable grading labs. I recommend checking out our go-to lab diamond dealer, Clean Origin.

Clean Origin does lab diamonds, and only lab diamonds. Not a mined diamond in sight. They have video for you to observe any diamonds with blue nuance. All of their diamonds are certified. The GIA, IGI, and GCAL diamond certificates will tell you which growth process was used.

Clean Origin Diamond Viewer Features

If you can't tell which diamonds in their inventory have blue nuance, don't worry a diamond expert is standing by. They also provide a 100-day return policy for their diamonds, just in case you didn't get what you're looking for.

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