CVD Diamond

How to tell if a Diamond was Created in a Lab?

Posted on January 31, 2022April 29, 2025 by Chris Galey

The diamond industry is striving with a flourishing supply of all types of diamonds. This includes man made diamonds natural diamonds, diamond hybrids, and even clarity-enhanced diamonds.

As lab grown diamonds are produced by two methods, CVD diamonds & HPHT synthetic diamond-making methods. It has led to a sufficient supply of man made diamonds in the market. However, this has also increased the level of difficulty for retailers and customers to differentiate between lab grown loose diamonds and natural diamonds.

It is easy to determine which is a diamond stimulant, an enhanced diamond, or even a diamond hybrid, but distinguishing between lab grown diamonds and natural diamonds is a hard task.

As many consumers have become conscious and aware, they prefer to purchase man made diamonds because of the esteemed benefits; Eco-friendly, cheaper than natural diamonds, doesn’t have fun conflicts. This results in concern among jewelers and consumers to identify man made diamonds, and whether lab grown fancy diamonds can be identified by expert gemologists or gemological labs.

Visual Properties of Man Made Diamonds

Diamonds have the same physical, chemical, and optical properties as natural diamonds. However, there are some characteristics of CVD diamond & HPHT synthetic diamond that trained gemologists with special types of equipment can distinguish.

CVD Diamond

Abnormal fluorescence colors
Fluorescence color patterns detected
Even the distribution of colors
Graining patterns not detected
Banded strain patterns detected
Intermittent dark pinpoint-size inclusions
Inscribed on the griddle by a diamond grading institution

The diamonds created by the CVD diamond making method show a red-orange fluorescence under U.V light. These CVD diamonds have intermittent black pinpoint-size inclusions and contain some particles of non-carbon in them. All CVD diamonds can be determined by looking under a UV light irrespective of what treatment they might have gone through.

HPHT Synthetic Diamond

Irregular color distribution within the diamond
Abnormal fluorescence colors
Graining patterns detected
No strain patterns detected
Intermittent phosphorescence
Metallic flux inclusions detected
Inscribed on the griddle by a diamond grading institution

The HPHT synthetic diamonds can be distinguished from natural diamonds, by the metallic flux inclusions they possess. HPHT synthetic diamonds can be white diamonds or even colored diamonds. Their carat size varies between 0.5-10 carats.

Different Types of Diamonds

Man made diamonds can be categorized into different types, depending on the clarity and the type of impurity it consists of in the carbon lattice. Powerful equipment such as an infrared spectrometer (used to determine functional groups in molecules).

The 4 types of Classification Based on Impurities are: Ia, Ib, IIa, IIb

Type Ia: In this type of white diamond, there are nitrogen clusters within the diamond crystal lattice. Type Ia diamonds are pale yellow and 95% of the diamonds which are mined worldwide are of this type.

Type Ib: In this type of loose diamond, single nitrogen atoms are present throughout the carbon lattice of a diamond. All lab created diamond which are yellow is of this type, while 0.1% of mined diamonds are this type.

Type IIa: This type is the purest form of fancy diamond that can be found, (Type IIa)consists of no or marginal impurities in its crystal lattice. All lab grown white diamonds or colorless diamonds are of this type, while 1%-2% mined diamonds are of this type (white to pink).

Type IIb: A type 2b (type IIb) loose diamond has the presence of boron impurities in it. All lab grown blue fancy diamonds are of this type, while in the case of mined blue diamonds, only 0.1% are of this type.

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Methods to Identify the Lab Grown Diamond

There are several technical ways that can be used to check whether a diamond is lab-made or not. But there are certain methods that can be implemented on a personal level to check whether or not a diamond is created in a laboratory, and we are here to list the same. So when you start your inspection of a diamond here are a few things to keep in your mind:-

Certification

One method to identify lab-created diamonds is through certification. When a diamond is created in a laboratory, it often undergoes rigorous testing and analysis to determine its origin and quality.

Look for certifications from reputable gemological laboratories like GIA (Gemological Institute of America), GCAL (Gem Certification & Assurance Lab) or IGI (International Gemological Institute), often specifying if a diamond is lab-created.

These certificates provide detailed information about the diamond’s characteristics, including color, clarity, cut, and carat weight. They may also include specific language indicating that the diamond is lab-created or synthetic. However, it’s important to note that not all lab-created diamonds come with certificates.

Color

Checking the color of the diamonds is a good enough technique to learn whether or not it is lab-grown. As most of them are either bright yellow or blue.

What you need to know is that both yellow and blue are rare colors to find in the market (for natural diamonds), and hence the prices of these gems are soaring. Stones with extraordinary or on the face color, are generally lab-made. However, this is not the only sign you can bank upon.

Disclosure

You can figure out whether a diamond is lab-made or not by looking out for responsible disclosure. A lot of times in the industry, there are non-disclosed diamonds too, which could be lab made diamonds sold as natural ones.

However, this is rare as most of the time manufacturers of lab grown diamonds are legitimate and upfront about their stones. A lot of them have inscriptions made with lasers on the gem which state the diamond is lab-grown.

Inclusions

Natural or lab grown diamonds both have a great number of inclusions present in them which hamper their clarity to an extent. Natural diamonds that grow inside the earth, the inclusions found in them are naturally occurring. Like bird feathers, flecks of other gems, or clouds.

However, lab made diamonds are made with chemicals, solutions, and metals. Hence a common inclusion present in these gems is most often metallic. These are usually not found in natural diamonds, because for obvious reasons.

Either way inclusions in both of these diamonds are hard to detect and you’d usually need a 10x magnification to even get an idea if there are inclusions present inside them.

Scientific Type

Scientific type or Type IIa tests are used to categorize lab made diamonds. There are four categories, and these categories are based on how much the diamond is contaminated with carbon lattice, at the atomic level of the diamond. To identify these impurities a piece of powerful equipment like an infrared spectrometer is used for detection.

The types are

Type Ia – It has about 98% mined diamonds.
Type Ib – It has maximum synthetic diamonds which are yellow, with 0.1% mined diamonds.
Type IIa – It is a completely synthetic diamond that is colorless, with about 1% or 2% of a mined diamond.
Type IIb – It is again completely synthetic but blue-colored diamonds, with about 0.1% mined blue diamonds.

The best indicator to bank on whether or not a diamond is lab-grown is, to check if it is a Type IIa diamond or not. What it means to belong to the Type IIa variant is how much pure carbon is used to make that diamond.

Even less than 2% of the time natural diamonds turn out to be a Type IIa, however, almost all lab grown diamonds are Type IIa. Thus, if the type test categorizes the diamond to be Type IIa it is a pretty good indicator that the diamond you are holding is a lab made diamond.

Basic Equipment

Simple testers are available at the jewelers and these can help you figure out whether the diamond is lab made or not. These tests are usually to check the thermal conductivity level of the diamonds, this is done due to the fact of how diamonds are good conductors of heat. These thermal tests help us identify whether they are lab made or natural diamonds.

Let us give a few more tips regarding these conductivity tests so that you can figure them out better. So, yellow and mined white diamonds aren’t electrically conductive. On the other hand, blue diamonds are because of the boron present in them.

Also, some white diamonds are grown with the HPHT process which can make them conduct electricity, though they are colorless. This test of conductivity is more accurate for yellow diamonds.

Advanced Equipment

There exist advanced techniques too, that will for sure help you identify lab made diamonds. For instance, The Fourier transform infrared spectrometer (FTIR) or the energy dispersive X-ray fluorescence (EDXRF) are devices that can be used to identify any indication of metal in diamonds.

This metal usually is found in lab made diamonds, as it comes from the molten metal solution it is made in the lab. Another device that can be used is a cathodoluminescence (CL) spectrometer; it can show the sectors where a diamond can grow.

Naturally found diamonds usually just have octahedral growth, that is growth from six sides. Whereas diamonds made through the HPHT process can have either a cubical or octahedral growth.

DeBeers, the diamond mining company, has over the years come up with two machines that can identify diamonds very correctly. One of them is, DiamondSure, this machine calculates the very specific wavelength of light absorption in the lab made diamonds. This is done at the beginning stage.

As you look for more advanced technology, which also means it would be more costly, there is the DiamondView machine, which traces fluorescence patterns in diamonds with the help of shortwave ultraviolet imaging.

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Conclusion

Following all these techniques at once might get a little hard so you won’t instantly be able to recognize whether or not your diamond is lab-made. However on the bright side, today a great number of diamond manufacturers and merchants responsibly disclose that they sell lab grown diamonds.

This in turn helps them with their business. Let’s also give you this reassurance that several major and popular diamond suppliers have started purchasing diamond testing machines. This again leaves no stone unturned for you to identify whether or not your diamond is lab made or not.

The industry as a whole has gone to lengths to make sure that when a diamond is being sold as being told it is natural, it ought to be it. And, you can trust the market with the same, because even they work on word of mouth and customer satisfaction. Which is colloquial in the business.

FAQs

How is a lab grown diamond made?
Lab created diamonds are made using either High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD) processes, which simulate the natural conditions under which diamonds form in the earth’s mantle.

Are lab created diamonds environmentally friendly?
Lab created diamonds have a smaller environmental footprint compared to mined diamonds because they do not require large-scale mining operations.

Are lab grown diamonds a good choice for engagement rings?
Lab man mad diamonds are an excellent choice for engagement rings due to their beauty, durability, and lower price point compared to natural diamonds.

Are lab created diamonds as valuable as natural diamonds?
Lab grown diamonds can be just as beautiful and durable as natural diamonds, but they are typically priced lower due to their controlled production process and lower mining impact.

How much is a 3 carat lab grown diamond?
The price of a 3-carat lab grown diamond can vary depending on factors such as its color, clarity, cut quality, and the specific retailer. Generally, you can expect to pay anywhere from $3,000 to $40,000 for a 3-carat lab grown diamond.

Why CVD Diamond Pass Tester and HPHT Can’t?

Posted on January 15, 2022June 4, 2024 by Martin Mora

Are you considering purchasing a lab grown diamond but somehow tend to have doubts regarding them? Like whether they are real diamonds? How trustworthy are they? Will they be able to pass a diamond tester?

Well, no need to worry, as we come packed with an answer to all your questions. Let us first clear out some basic misconceptions which are withheld by many individuals.

Are Lab Grown Diamonds Real Diamonds?

Yes, lab grown diamonds are definitely real diamonds! They possess the same physical, chemical, and optical properties as natural mined diamonds. Just because they are created within a human-controlled environment does not in any way change the fact that lab-grown diamonds are real diamonds.

Lab Grown Diamonds are Made Using Two Methods:

- CVD: Chemical Vapour Decomposition Method
- HPHT: High-Pressure High-Temperature Method

What are CVD and HPHT Methods?

CVD is an acronym for ‘Chemical Vapour Decomposition’. This method is carried out to create type lla diamonds, which are one of the purest forms of diamonds. To give you an example, the Kooh-i-noor is also categorized as a type lla diamond.

To create a precious gem via the CVD method, a diamond seed is placed in a chamber which recreates the conditions that are found under the earth’s surface. The chamber comes equipped with a pure, rich carbon plasma. As soon as the process starts, carbon atoms get deposited on the material, creating layers and layers of carbon. By the end of the process, a rough man-made diamond is formed.

HPHT is an acronym for ‘High-Pressure High Temperature’. This method though produces a real diamond, the diamonds at times contain certain metal impurities. Most of the diamonds formed by the HPHT process aren’t as pure as required. Thus, many diamonds formed by this method aren’t categorized as type lla diamonds.

To create a lab-grown diamond by the HPHT process, a diamond seed is put inside a chamber along with graphite and certain metals that act as a catalyst. The chamber then creates an environment of 60,000 ATM and 2500°C, somewhat similar to what we find under the earth’s crust. By the end of the process, a rough lab-grown diamond is formed.

Difference Between Hpht vs. Cvd diamond

HPHT (High Pressure High Temperature) diamonds simulate Earth’s mantle conditions where natural diamonds develop. This technique involves heating and pressurizing carbon to 1,500–2,000 degrees Celsius and 5–6 GPa. It controls impurities and crystal quality, producing diamonds with fewer inclusions and uniform quality. Its high energy and pressure needs make it more expensive, although advancements in technology are lowering costs. HPHT lab-grown diamonds can generate more colors, including fancy colors, with element additions or treatments. They have dominated the market for larger, high-quality diamonds for industrial and gemstone uses, especially in exotic colors.

However, CVD diamonds are created by depositing carbon atoms onto a substrate in a controlled environment at lower temperature (700 to 1,300 degrees Celsius) and pressure. This technique may struggle to control contaminants, but the diamonds may vary in grade and inclusions. Its reduced temperature and pressure requirements make it cheaper than HPHT, and ongoing improvements lower prices of CVD diamonds. CVD diamonds are usually near-colorless to mild yellow, however advances are increasing color options. They are popular for gem-quality jewelry diamonds and smaller industrial diamonds. Please note that CVD Diamond engagement rings are quite popular these days.

CVD uses energy but has a smaller environmental impact than HPHT. Both approaches are being improved for sustainability. HPHT diamonds have traditionally been more popular, especially in larger sizes and fancy colors, while CVD diamonds, especially smaller ones, are gaining market share for industrial and gem-quality applications. CVD or HPHT-grown diamonds have the same physical, visual, and chemical qualities as natural diamonds, despite any distinctive traits before cutting and polishing. Both are pure carbon and hard. CVD and HPHT diamonds look the same and cost similarly.

Lab Grown Diamonds are Not Diamond Simulants

There is a fair misconception among people that lab grown diamonds are created using diamond simulants or are diamond simulants completely. Both these perceptions are false and have no logical basis.

Diamond simulants are fabricated using Cubic Zirconia and Moissanite, which are in no way related to diamonds. They only tend to look like diamonds however, they possess different physical, chemical, and optical properties in comparison to lab grown diamonds.

How Pure are Lab Grown Diamonds in Comparison to Naturally Mined Diamonds?

The purity of a diamond is represented by the type they are categorized in. There are mainly two types of diamonds:

Type lla or la: A type lla diamond is considered to be the purest form of diamond, as there is an absence of any class of impurity.

When naturally mined, only 5% of the rough diamonds are pure enough to be categorized as type lla. The rest are bound to have some impurity and be categorized as type la. Nitrogen, which is a commonly occurring impurity among diamonds, is responsible for the yellow tinge that many of these precious gems possess.

While, in the case of lab grown diamonds, the majority of diamonds created by the CVD method are categorized as type lla. This is because of the absence of nitrogen in the manufacturing process. However, diamonds produced by the HPHT method tend to contain some metal impurities, which tend to hinder their appearance.

Which Diamond Will Pass the Test Conducted by a Diamond Tester?

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A natural diamond that has been mined from beneath the earth’s crust will definitely pass the tester. Irrespective of its type or shape, the natural diamond is a ‘diamond’ that will pass the test.

A CVD diamond will pass the test as the diamonds produced by this method are mostly categorized as type lla. They have minimal to no impurities present in the diamond.

An HPHT diamond might not pass the test with ease, as the diamond created by this method may have excess impurities (mostly metal impurities) present in it. This may be caused due to the presence of a metal influx in the manufacturing process. Which, in turn, hinders the diamond’s chemical composition and physical properties.

This does not mean that HPHT diamonds are not real diamonds, it just indicates that some diamonds formed by this process consist of excess impurities.

However, if an HPHT diamond has minimal to no impurities present in its composition, those diamonds will easily pass the test. Check out our lab created diamond rings here.

Where to Buy CVD or HPHT Diamonds?

Since they have the same qualities as actual diamonds, CVD and HPHT diamonds are both real. They are visually identical and have comparable prices. In case you want to buy CVD diamond or HPHT diamond, you can get in touch with us at Loose Grown Diamonds and use our promocode for the best prices and amazing offers.

Conclusion

Finally, concerns regarding the authenticity of lab-grown diamonds are dispelled by the fact that both CVD and HPHT lab-grown diamonds have the same attributes as natural diamonds. HPHT or CVD diamond certificates further confirm the same. Both forms of diamonds pass diamond tests and are real, however CVD diamonds might have purer compositions. For competitive pricing and special deals on these genuine lab-grown diamonds, you can get in touch with our gemologist at LGD.

FAQs

What is a CVD diamond?

CVD diamonds are produced in laboratories through the use of the Chemical Vapour Deposition process. There are numerous CVD diamond wholesale companies in the market. Loose Grown Diamonds is one of the best, with the highest quality diamonds.

Do CVD diamonds pass a diamond tester?

Yes, Lab-created diamonds pass the same tests as natural diamonds. They pass the standard diamond test with the same result because they have identical characteristics and composition to natural diamonds.

How are CVD diamonds detected?

A variety of techniques, such as spectroscopy and microscopy, are used to determine wether a stone was created by the CVD method.

Can fake diamonds pass the diamond tester?

While imitation diamonds might not pass diamond testing, genuine CVD/HPHT diamonds usually do.

Are CVD and HPHT Diamonds Real?

Indeed, lab-grown diamonds having the same characteristics as natural diamonds are both genuine, including CVD and HPHT diamonds.

Are CVD Or HPHT Diamonds Better?

Although both CVD and HPHT diamonds have special benefits, the decision between them is based on elements like cost and purity. Generally, CVD diamonds value less compared to HPHT due to lower pressure and temperature requirements in the making process.