back to Everything Diamonds

Do Lab Created Diamonds Test as Real?

by Lucy Coleman
Last updated on September 16, 2023
Diamond eternity bands. Do lab created diamonds test as real.

Diamond tests can determine if a diamond is real or not. Testing diamonds is a quick and easy way to tell if you have a fake diamond. But do lab created diamonds test as real?

The short answer is yes. But let’s delve a little deeper into this topic and find out why. Read on to find out more about lab grown diamonds, diamond alternatives, and diamond testers.

What Are Lab Grown Diamonds?

Lab grown diamonds are now more popular for diamond jewelry, especially engagement rings. What many people do not know, however, is what a lab grown diamond is. People also do not know how it differs from a mined diamond.

Lab grown diamonds do not come from the earth. And they don’t go through processing facilities. But they still need cutting and polishing like natural diamonds.

How Are Lab Grown Diamonds Created?

Lab grown diamonds grow in a lab under conditions of high temperature and pressure. Put simply, they are diamonds that were grown under lab conditions.

There are two processes to create a lab grown diamond. The first is chemical vapor deposition (CVD) and the second is high-pressure high-temperature (HPHT).

Both CVD and HPHT diamonds start with a diamond seed made of carbon. Next, the carbon seed is subjected to conditions where the carbon structure can grow into a lab diamond.

Natural Diamonds Versus Lab Diamonds

Lab grown are real, just like natural diamonds.
Lab grown are real, just like natural diamonds.

The main difference between a lab grown diamond and a natural diamond is where they come from. Otherwise, they have the same chemical properties–there is not much else that differs.

Natural Diamonds

Natural diamonds form when pure carbon atoms bond and arrange in a specific structure. Carbon bonds are very strong so they need extreme pressure and heat for this to happen.

Earth mined diamonds take billions of years to form. Once they form, they come near the surface of the earth. They do this via volcanic eruptions or other natural processes.

Established diamond mines exist all over the world to mine these diamonds.

Lab Grown Diamonds

Lab grown diamonds are pretty much the same as natural. The only difference is that they come from a lab instead of deep under the earth’s crust.

Lab diamonds have the same carbon bonds and same chemical properties. They have the same hardness and other physical properties as natural diamonds.

Experts cut and polish lab grown diamonds just like they do natural diamonds. They are subject to the same grading report from the Gemological Institute of America and other diamond grading organizations.

Are Lab Grown Diamonds Real?

Loose, oval-shaped lab grown diamonds.
Loose, oval-shaped lab grown diamonds.

Lab grown diamonds are identical to mined diamonds both physically and chemically. They are definitely real.

Many people call a lab grown diamond a synthetic diamond. And while it is true that they are synthetic, the name often infers that it is fake.

A lab grown diamond is real no matter the name given to it.

For an engagement ring or other jewelry, lab diamonds are a great choice. They have the same quality as their natural counterparts and are a more ethical choice.

Diamond Alternatives

There are diamond alternatives or diamond simulants that are imitations of a diamond. These gemstones are not real diamonds, but they may appear similar.

Diamond simulants are popular for costume jewelry and for higher-end fine jewelry. Some people may even choose a diamond alternative for their engagement ring to save on the cost of diamonds.

All of these diamond alternatives are considered fake diamonds. They may be natural stones, but they are not real diamonds.

Diamond alternatives usually have a similar look but there are ways to tell the difference with the naked eye or a diamond tester. Even if they look the same as a natural diamond, a jewelry expert will be able to tell the difference.

Cubic Zirconia

Cubic zirconia (CZ) is one of the most popular diamond alternatives. It is made of zirconium dioxide in crystal form.

When looked at compared to a real diamond, cubic zirconia will have a rainbow effect. It does not give off the same brilliance that a diamond does.

Because it is not a diamond, CZ is not as hard. Therefore, it is more susceptible to scratches, dents, and fogging over. This makes it harder to pass along to future generations.

This man-made gemstone is very inexpensive. You can easily find a one-carat cubic zirconia engagement ring for less than $20. Because it is so inexpensive, CZ essentially has no market or resale value.

White Sapphire

White sapphire is a natural gemstone that resembles a diamond. It is relatively rare but not high in demand making it more affordable than diamonds.

Sapphire is almost as hard as a diamond, making it very durable. A white sapphire engagement ring is a great option for someone who wants something different than traditionally mined diamonds.


Moissanite is another natural gemstone that resembles a real diamond. It is made of silicon carbide, a rare mineral.

Natural moissanite is rare so most of it is lab grown.

The big difference between moissanite and a diamond is their optical properties. Like CZ, moissanite will reflect more rainbow light than a diamond will, which makes it less brilliant.

Moissanite costs less than mined diamonds or lab diamonds.

Using a Diamond Tester to See if Lab Created Diamonds Test as Real

Testers are helpful, but not foolproof.
Testers are helpful, but not foolproof.

There are many types of diamond testers and they don’t all work the same. Most of the time, one diamond tester is not enough to truly tell you if you have a real diamond or not.

That being said, a diamond tester can still help you sort through your diamond collection. It can also give you an idea of whether or not your diamond is lab grown or real.

Diamond Tester Pens to Test Lab Created Diamonds

The most common type of diamond tester is a small device that measures thermal conductivity of the stone.

Diamonds have high thermal conductivity so if the stone also has a high thermal conductivity, the tester will show it as real.

A real diamond and lab grown diamond will pass this diamond test. Moissanite also has a high thermal conductivity. So sometimes moissanite can give a false positive.

CZ and white sapphire do not conduct heat well so they will not pass the test.

Does a Diamond Tester Work?

These types of diamond testers work to an extent. They cannot, however, tell between a lab diamond and a natural diamond. Lab grown diamonds test the same as natural diamonds but can sometimes give a false negative.

Depending on the tester, they also may not be able to tell the difference between a diamond and moissanite.

If you really want to know the specifics of your gemstone, it’s best to also perform other tests like checking the stone under magnification.

How to Tell if You Have a Lab Grown Diamond

Solitaire engagement ring.
Solitaire ring.

If you want to know whether you have a lab created diamond or a natural diamond, you need to look for more information.

Check the Certificate Instead of Doing a Lab Created Diamonds Test

In the diamond industry, all diamonds, including lab grown diamonds, are certified. The GIA or other gemological institute will give each diamond a certificate to evaluate the diamond and authenticate it.

There should be a microscopic engraving that shows the certificate number. Lab grown diamonds will have “lab grown” or “LG” engraved on them to denote that they are lab grown diamonds.

You will need to bring your diamond to a jeweler to check this engraving as you cannot see it with the naked eye.

Other Ways to Test Lab Created Diamonds

There are more tests that someone can perform to tell mined diamonds from lab diamonds. A UV ray test can measure the fluorescence of a diamond, although it is a relatively new and expensive test.

Bottom Line: Should You Use a Diamond Tester to Test Lab Created Diamonds?

Diamond testers are great for spotting fake diamonds. It is also fun to see how they work.

In the end, if you are unsure and want to know more about your diamond, you may need more than a thermal conductivity test.

The best way to tell if you have a lab diamond is to take it to a jewelry expert. They can perform the right tests or send it to a lab that can. That way, you can be confident in the answer you get.

Shop For Lab Grown Diamonds

Lab created diamonds are 20%-40% less expensive than mined diamonds.
Lab created diamonds are 20%-40% less expensive than mined diamonds.

Lab diamonds are a great option for an engagement ring because they are the same as mined diamonds, but at a more affordable price.

They also cost around 20%-40% less than natural diamonds. This makes lab diamonds perfect for your ring.

Clean Origin Diamonds

Clean Origin has the best selection of loose diamonds and engagement ring settings. You can shop for the highest-quality, ethical, and responsibly-sourced fine jewelry at your fingertips!