How to Identify Lab-Grown Diamonds

How to Identify Lab-Grown Diamonds

If you’re trying to distinguish between lab grown diamonds and natural diamonds, you’ve come to the right place!

How to Identify Lab-Grown Diamonds

In this Learning Guide, I’ll be addressing some of the most commonly asked questions regarding the identification of synthetic diamonds versus mined diamonds. These questions include:

  • How can you identify lab grown diamonds?
  • Is it possible to differentiate between lab grown diamonds and mined diamonds?
  • Are lab grown diamonds identical to natural diamonds?
  • Where can you go to identify lab grown diamonds?

What are Lab Grown Diamonds?

Lab grown diamonds are typically produced through two methods: high pressure high temperature (HPHT) or chemical vapor deposition (CVD). In both processes, a diamond seed is utilized within a chamber.

In the growth process of an HPHT synthetic diamond, a diamond seed can come from HPHT diamonds, natural diamonds, or a CVD diamond seed.

On the other hand, CVD creation only employs diamond seeds of Type IIa, which contain no nitrogen or boron impurities. Type IIa natural diamonds consist solely of pure carbon atoms and are rare, representing only 1-2% of rough diamond crystals in the industry. Thus, a CVD diamond seed is considered top-notch.

However, HPHT laboratory grown diamonds are also capable of producing diamonds that are equivalent in quality to CVD diamonds. In other words, neither method is inherently better than the other.

RECOMMENDED: HPHT Diamonds vs CVD Diamonds

Are Lab Grown Diamonds Authentic Diamonds?

As people become more informed about synthetic diamonds, it’s encouraging to see that they are becoming better acquainted with the numerous names they go by.

Lab grown diamonds are commonly referred to as:

  • Synthetic diamonds
  • Man-made diamonds
  • Cultured diamonds
  • Created diamonds

However, the use of “cultured diamonds” can be misleading, as they are not pearls.

One of the biggest misconceptions among diamond buyers is that lab created diamonds are fake diamonds or diamond simulants. In reality, lab grown diamonds are genuine diamonds with identical physical, chemical, and optical properties to earth grown diamonds. This also applies to lab grown sapphires or other gemstones, which have the same composition as natural sapphires despite being created in a lab environment.

The process of growing diamonds is much quicker than waiting for gem-quality mined diamonds, which can take billions of years to form. The main distinction between the two is their origin: one is mined from the earth, while the other is created in a laboratory.

Simulated diamonds or diamond alternatives, in contrast, usually refer to other colorless gemstones or man-made materials such as moissanite, cubic zirconia, white sapphire, white topaz, and white zircon.

What is the difference between simulated diamonds and lab created diamonds?

Well, simulants lack the same brilliance, durability, and chemical makeup as a natural diamond, while lab created diamonds possess all of these characteristics.

Is It Possible To Differentiate Between A Lab-Created Diamond And A Mined Diamond?

One of the most frequently asked questions regarding lab-grown diamonds is how to distinguish them from earth-mined diamonds. Ethical consumers want to ensure that they are not supporting conflict diamond practices.

The good news is that we only recommend engagement ring brands that follow the Kimberley Process, but some people may want to be more confident in their purchase of an ethical engagement ring. This is perfectly understandable.

However, I have both good news and bad news.

The good news is that no one will attempt to sell you a conflict diamond at lab-grown diamond prices. Those who participate in these schemes know that there is always another buyer willing to pay a different price.

Now for the bad news.

It is impossible to tell the difference between lab-grown and mined diamonds. On a diamond tester, both will test positive as a diamond.

Before you become too alarmed, let me explain.

As customer, you will not be able to differentiate between a lab-grown diamond and a natural diamond properly. Why is that?

Synthetic diamonds have the same optical properties as natural diamonds, meaning that visually, there is no difference between a lab-grown diamond and a mined diamond with the same diamond grades.

However, a trained gemologist or diamond expert can tell the difference between a lab-grown diamond and a mined diamond.

How Can Gemologists Differentiate Between Lab-Grown and Natural Diamonds?

It’s important to note that not all gemologists are trained to identify lab-grown diamonds. The most highly regarded gemology degree in the jewelry industry is the Graduate Gemologist (GG) Degree from the Gemological Institute of America (GIA).

However, possessing a GG degree does not necessarily mean that a gemologist specializes in identifying lab-grown diamonds. They may have learned about them during their studies, but they may not be experts in this area.

Some local jewelers may have the necessary equipment to distinguish between lab-grown and natural diamonds. Here are some ways in which a gemologist or jeweler can assist in identifying lab-grown diamonds.

  1. Fluorescence

It’s worth noting that even if a lab-grown diamond does not exhibit fluorescence, a gemologist can induce fluorescence using the Diamond View machine at the GIA. This machine was developed by the GIA specifically to identify lab-grown diamonds.

The Diamond View machine uses UV light to create a fluorescent image of the diamond. When viewed under this light, the diamond will glow blue. However, lab-grown diamonds tend to fluoresce more brightly than natural diamonds. HPHT diamonds will appear a brighter blue, while CVD diamonds will fluoresce orange.

It’s important to remember that not all diamonds exhibit fluorescence, so this method may not be effective in identifying all lab-grown diamonds.

  1. Growth Patterns

The Diamond View machine not only produces a fluorescent image of the diamond, but it also creates a scan of the diamond on a computer. Gemologists can then use this scan to detect the growth patterns of lab-grown diamonds.

While lab-grown diamonds and earth-mined diamonds share the same durability and hardness, their original growth formations differ. By analyzing the growth patterns, gemologists can distinguish between lab-grown and natural diamonds.

  1. Phosphorescence

The GIA’s Diamond View machine is also capable of measuring diamond phosphorescence. Phosphorescence refers to the residual glow left after the removal of UV light. This feature is relatively uncommon and is only found in about 0.001% of diamonds.

Due to the rarity of phosphorescence, multiple tests are required to ensure accurate identification. This approach allows for a more comprehensive assessment, as different tests may be better suited for different diamonds.

  1. Inclusions

It should be noted that the method of detecting lab-grown diamonds is not foolproof. If you purchase a diamond with a clarity grade of VVS or higher, which indicates no inclusions under magnification, it may be more difficult to determine whether it is a lab-grown or natural diamond. This is one reason why VVS diamonds are priced so highly.

However, an actual diamond grading lab has better methods for detecting even the smallest blemishes.

Compared to earth-mined diamonds, lab-grown diamonds are less likely to have as many different inclusions. Mined diamonds are formed in the earth where various minerals and impurities can seep into the crystal growth process, and the diamond crystal grows around them.

Synthetic diamonds, on the other hand, are created in a controlled lab environment and are therefore much more limited in terms of what they come into contact with. Lab-grown diamonds are known for having graining patterns or metallic inclusions made of graphite. While there are many different types of inclusions, these are some of the more common ones found in lab-grown diamonds.

  1. Type II Diamond Machine

It’s important to note that not all jewelers or gemologists will have a Type II diamond machine readily available. As the name suggests, this machine is designed specifically to detect Type II diamonds.

How a Customer Can Identify Lab Grown Diamonds

Buy a Certified Lab Grown Diamond

I understand that identifying lab grown diamonds can be difficult for customers, but there is a solution: purchasing a certified lab grown diamond. A grading report will indicate whether the diamond is lab grown and which creation process was used. However, it’s important to note that not all grading labs are equal, so be sure to research reputable labs for lab grown diamonds.

While I recommend only buying GIA or AGS certified natural diamonds, there are more reputable grading labs for lab grown diamonds. Additionally, if you’re in the market for a lab diamond, you may be interested in knowing which online store we consider to be the best diamond seller currently.

Purchasing a diamond with the desired grades is important to buyers, and a grading report provides that assurance. Unfortunately, grading reports can be falsified, issued by unknown labs or self-certified brands like Diamond Foundry.

To ensure authenticity, buyers should only purchase lab diamond engagement rings from reputable retailers. These retailers typically provide grading reports that can be verified by entering the report number on the grading lab’s website.

Send It to a Grading Lab

Grading labs can help identify if a diamond is lab grown or natural. It’s also possible to get a diamond engagement ring certified by a grading lab. GIA and AGS are highly recommended for grading natural colorless diamonds.

For both lab grown diamonds and natural diamonds, GIA is a reliable choice for grading. To get a diamond graded by GIA, the unmounted diamond needs to be sent to their grading facility, with a fee of around $125 for a lab diamond report. GIA also offers grading reports for lab created fancy color diamonds.

If you’re looking for a more affordable option to get a lab diamond graded, the International Gemological Institute (IGI) is a popular choice. They provide common grading reports and were considered the best before GIA updated their reports.

Laser Inscription

When purchasing a lab-grown diamond from a trusted grading authority, it is possible that the diamond may have a laser inscription, sometimes called a Gem Scribe number, on the stone. To locate the inscription, one will need a jeweler’s loupe. If one does not have a jeweler’s loupe, they can take the diamond to a local jeweler who can read the inscription to them.

The laser inscription on a diamond consists of a combination of letters and numbers that are written on the girdle, which is the edge that goes all the way around the diamond. By matching the number on the diamond with the grading report or typing the number online into the grading lab’s website, the authenticity of the diamond can be confirmed.

It should be noted that not all diamonds with a grading report have a laser inscription. However, large grading labs such as the GIA offer the option to inscribe diamonds for an additional cost.

Having a laser inscription on a diamond can be beneficial in the event of theft or switching. While diamond theft and switching are unfortunate events, they do happen, and many people claim that their diamond has been switched by different companies. A laser inscription on the diamond can confirm that the diamond received from a jeweler or repair shop is the same one that was originally purchased.

If someone steals a diamond ring that has a laser inscription and tries to sell it to a pawn shop, the pawn shop will analyze the diamond and look up the number on the laser inscription. If the inscription has been reported as stolen (which would require the owner to contact the grading lab after the theft), the pawn shop will keep the diamond and alert the authorities.


Therefore, it is recommended to use a reputable grading lab like the GIA, which is the industry leader, for both grading and laser inscription services. This provides an added layer of protection to ensure that the diamond is authentic and can be traced if it is lost or stolen.

A laser inscription on a lab-grown diamond from a trusted grading authority is a valuable tool to confirm the authenticity of the diamond and protect against theft or switching. One can easily match the number on the diamond with the grading report or typing it online to confirm its authenticity. It is recommended to use a reputable grading lab like the GIA to ensure the highest level of protection.


Distinguishing between mined and lab-grown diamonds is not always possible with a visual inspection alone. However, there are several methods to identify lab-grown diamonds, all of which require the assistance of a gemologist, jeweler, or grading laboratory.

To ensure a reliable purchase, it is important to buy diamonds from reputable brands with many positive reviews and an easy return process. A lab-grown diamond should also be certified by a trustworthy grading lab.

Most online diamond retailers sell only certified diamonds, but larger retailers like Jared, Zales, and Kay often have the majority of their diamonds uncertified, both lab-grown and natural. These retailers also tend to have minimum diamond clarity and color grades, and they charge higher markups for certified engagement rings than online diamond retailers.

One can feel confident in purchasing a lab-grown diamond online from a popular retailer like James Allen or Brilliant Earth. These retailers provide real lab-grown diamonds, and their certification process ensures authenticity.

Generally, identifying lab-grown diamonds requires assistance from professionals, and it is crucial to purchase from reputable brands and certified lab-grown diamonds from trustworthy grading labs. Online diamond retailers such as James Allen and Brilliant Earth are a reliable option for purchasing lab-grown diamonds.

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