How Are Lab Grown Diamonds Made?

How Are Lab Grown Diamonds Made?

Curious about the production process of lab-grown diamonds?

You’ve come to the right source.

This guide will provide you with the answers to the following inquiries:

  • What are lab-grown diamonds?
  • How are lab diamonds created?
  • Are lab diamonds authentic?
  • How do HPHT and CVD lab diamonds differ from one another?

Mined Diamonds and Lab Grown Diamonds

Lab-grown diamonds have been referred to using a variety of terms, including synthetic diamonds, man-made diamonds, and cultivated diamonds.

Unfortunately, some of these labels have given lab diamonds a negative connotation.

Many people mistakenly believe that a synthetic diamond is a diamond simulant, such as cubic zirconia or Swarovski crystals. However, it’s important to note that lab diamonds are genuine diamonds.

Confusing Lab Grown Diamond Names

Lab diamonds can be referred to using a variety of confusing names, including man-made diamond, artificial diamond, synthetic diamond, cultivated diamond, cultured diamond, and engineered diamond. Regardless of the name, lab diamonds are genuine diamonds, but it’s important to ensure that they come with proper gem certification.

Lab-grown diamonds are produced in an environment that imitates the natural process of diamond formation within the earth. While there are some differences between mined and lab-grown diamonds, the majority of their properties are the same.

Both mined and lab-grown diamonds possess the same chemical, physical, and optical attributes, and adhere to the Gemological Institute of America’s 4Cs of diamond quality. Both can also be officially certified.

There are several reasons why one might opt for a lab-grown diamond over a mined diamond, such as cost or concerns about diamond mining practices, including conflicts over obtaining conflict-free diamonds.

How Lab Diamonds are Made

The production of lab-grown diamonds typically involves two primary techniques: high-pressure high-temperature and chemical vapor deposition.

High Pressure High Temperature

Although the high-pressure high-temperature (HPHT) process is commonly regarded as the initial method for creating lab-grown diamonds, this isn’t entirely accurate. While the chemical vapor deposition (CVD) process was developed earlier, scientists were initially unable to produce colorless or large carat weight diamonds using this technique. Consequently, the HPHT process achieved these objectives first.

To produce an HPHT diamond, scientists replicate the conditions necessary for natural diamond formation. However, it wasn’t until the 1950s that consistently gem-quality HPHT diamonds were generated.

Most HPHT diamonds emerge with yellow or brown hues, necessitating treatments to modify their color. HPHT diamonds can also be altered to produce fancy colored lab-grown diamonds.

When producing HPHT diamonds, scientists employ a piece of diamond known as a diamond seed. This seed can be a sliver of a natural diamond, another HPHT diamond, or a CVD diamond.

The diamond seed is inserted into a mass of pure carbon, usually graphite. This assembly is then positioned within a chamber where it is subjected to immense temperatures and pressure, replicating the conditions found in the earth’s crust where natural diamonds are formed.

Temperatures utilized to produce HPHT diamonds reach over 2,000˚F, with pressures reaching around 1.5 million psi. These conditions cause the carbon atoms to melt and restructure around the diamond seed. Once the seed cools, the diamond crystal begins to grow.

Chemical Vapor Deposition

Chemical vapor deposition (CVD) is the other process used to create lab grown diamonds. Unlike the HPHT process, which uses immense pressure and high temperatures to grow diamonds, the CVD process starts with a diamond seed, which can be a natural, HPHT, or CVD diamond seed. It’s important for the diamond seed to come from a high-quality diamond to produce the best lab diamond.

CVD diamonds only use Type II diamond seeds, which do not have any nitrogen impurities. In natural diamonds, Type II seeds only occur in 3% of the world’s diamonds, while 97% of them are Type I diamond seeds. This means that CVD diamonds can create completely colorless diamonds that don’t need further color treatments.

Before the diamond seed is placed in the vacuum chamber, it gets cut and polished by a jeweler. Multiple diamond seed slices can be put in the chamber at once. Once the slices are sealed in the chamber, it’s filled with carbon-rich gases, such as methane and hydrogen. Inside the chamber, the mixture is heated at low pressure and high temperature, ranging between 900˚C and 1200˚C.

Under regular circumstances, heating at low pressures within the earth wouldn’t produce gem-quality diamonds. Instead, it would produce graphite or some other carbon form. However, with the CVD process, some of that hydrogen gets converted to atomic hydrogen, which provides the best environment for growing diamonds.

Once the CVD diamond has cooled, the diamond crystal begins to grow, just like HPHT diamonds. The CVD process had its roots, but scientists couldn’t produce colorless or larger carat weights in stone until recently. Now, the CVD process has become a popular method for producing high-quality lab grown diamonds.

How to Differentiate HPHT from CVD Diamonds

An untrained eye would not be able to distinguish between an HPHT diamond and a CVD diamond when placed side by side. Even the staff at popular jewelry retailers such as Jared or Kay may not be able to differentiate between the two processes.

To determine the difference between the two methods, it is necessary to purchase a certified lab diamond. Not all lab diamond certifications will disclose the process used. When it comes to natural diamonds, it is recommended to only obtain diamond certifications from respected authorities in diamond jewelry, such as the Gemological Institute of America (GIA) or the American Gem Society (AGS).

RECOMMENDED: Difference Between HPHT and  CVD Diamonds

Both the GIA and AGS offer certifications for lab grown diamonds, but other diamond labs are also recommended. The International Gemological Institute (IGI) certifies all lab grown diamonds and discloses the process used in their certification.

Recently, the GIA updated their lab diamond grading reports to provide more accurate information, including the process used to create the diamond. However, these updated reports may not be easily found among all diamond retailers.

De Beers has announced that they will begin producing lab-grown diamonds, following in the footsteps of the rest of the diamond industry. While a trained gemologist may be able to differentiate between the HPHT and CVD processes, the chances of the average consumer encountering this situation are slim.

Therefore, the question remains: is it necessary for consumers to know the difference between the two processes? The answer is, in truth, not really. From a buyer’s standpoint, the creation process has little effect on the most important factors when purchasing a diamond.

Both methods can yield colorless and eye-clean diamonds, with identical chemical composition, physical properties, and overall optical properties. Additionally, there is no discernible difference in price between the two.

In fact, the diamond industry itself cannot agree on which process is superior. Any differences between the two processes are mostly found in the mass production results, rather than in the quality of the diamonds themselves.

Difference Between HPHT Diamonds and CVD Diamonds

Production of Colorless Diamonds

There are two primary methods used to produce lab-grown diamonds: Chemical Vapor Deposition (CVD) and High Pressure High Temperature (HPHT). While both methods can create colorless diamonds, there are some differences between the two.

CVD Diamonds

CVD diamonds are produced using Type II diamond seeds, resulting in a colorless diamond. However, Type II diamonds are less common than Type I, making CVD diamonds harder to find. As a result, diamond companies that sell only CVD diamonds may be more expensive than those that offer both types.

The CVD diamond chamber is smaller and requires less energy than the HPHT method. While many people believe that lab-grown diamonds are more sustainable and environmentally friendly, the FTC warns that lab-grown diamond suppliers cannot advertise their diamonds as sustainable without backing it up.

Diamond Inclusions

On average, lab-grown diamonds have fewer inclusions than natural diamonds. Inclusions occur when the diamond crystal is growing, and different minerals come into contact with the rough diamond beneath the earth’s surface.

Lab-grown diamonds can still have inclusions, but they are limited to certain types. Compared to mined diamonds of the same grade, lab-grown diamonds generally have better clarity. HPHT diamonds have metallic inclusions caused by graphite, while CVD diamonds tend to have a mixture of different types of inclusions.

RECOMMENDED: Types of Diamond Inclusions

Blue Nuance and Brown Tints

HPHT lab-grown diamonds can have blue nuance, which is a blue hue caused by excess amounts of boron within the crystal. Slower growth during the diamond production process can reduce the likelihood of blue nuance.

If a diamond producer rushes the process, more diamonds may have blue nuance. However, it is important to note that blue nuance is different from diamond fluorescence, which is visible in UV lighting.

Lab grown diamonds have become increasingly popular over the years, mainly due to their lower price and sustainable nature. However, there are still many misconceptions and unknowns surrounding these man-made diamonds, including the issue of blue nuance and brownish tints.

Blue nuance, a blue hue found in HPHT lab diamonds due to excess amounts of boron within the crystal, is not well-known among lab diamond buyers. This is because it is rarely talked about, and lab diamond grading reports do not reveal it. While blue nuance can be minimized by growing the diamond slowly, rushing the process can result in more diamonds having this effect.

Some buyers prefer purely colorless lab diamonds and may switch to CVD diamonds, thinking they will avoid the issue of blue nuance. However, many CVD diamonds have a brownish tint, which is caused by vacancies within the crystal structure. Like blue nuance, this effect can also be minimized by growing the diamond slowly and carefully.

Neither blue nuance nor brownish tints are revealed on lab diamond grading reports, making it difficult for buyers to determine which diamonds have these effects. As a result, some argue that it is best to see the diamond in person rather than relying solely on online purchases. However, as long as the buyer is purchasing from a legitimate diamond retailer, they can be protected by the return policy if the diamond does not meet their expectations.

In the grand scheme of things, the presence of blue nuance or brownish tints should not be a major concern for most diamond buyers. While they may bother some, the majority of buyers cannot tell the difference, and both effects can be minimized by growing the diamond slowly and carefully. The same goes for diamond fluorescence.

The diamond industry often argues about which lab diamond creation method is better, but there is no definite conclusion. Both HPHT and CVD methods have their pros and cons, and both can create colorless diamonds that are virtually indistinguishable from natural diamonds. Companies that claim one method is better than the other are likely trying to push their own sales agenda without any gemological evidence to back up their claims.

Blue nuance and brownish tints are factors to consider when purchasing lab grown diamonds, they should not be the sole determining factor. Buyers should focus on purchasing from a reputable diamond retailer with a solid return policy, and should not worry too much about the diamond creation method as long as the diamond meets their desired specifications.

Do Lab Diamond Companies Have A Similar Business Model To Online Diamond Retailers That Sell Natural Diamonds?

Just like retailers that sell natural diamonds, lab diamond companies also offer a vast selection of loose diamonds on their websites. However, unlike natural diamond retailers, lab diamond companies actually make their own diamonds in their labs.

Lab diamond companies use two different methods to create diamonds: HPHT (High Pressure High Temperature) and CVD (Chemical Vapor Deposition).

HPHT lab diamonds are made by placing a diamond seed into a chamber that has extreme pressure and high temperature. This chamber replicates the conditions needed for diamonds to form naturally within the earth’s mantle.

CVD diamonds, on the other hand, are created by placing a diamond seed into a chamber filled with gases such as methane and hydrogen. The gases are then heated and ionized, causing carbon atoms to rain down onto the diamond seed and form a diamond crystal.

Both methods allow lab diamond companies to produce diamonds that are chemically and physically identical to natural diamonds.

Lab diamond companies often advertise their diamonds as ethical and sustainable because they are made in a lab and do not require mining. They also tend to be less expensive than natural diamonds of the same quality.

Unlike retailers that sell natural diamonds, lab diamond companies make their own diamonds in their labs. By using either HPHT or CVD methods, lab diamond companies are able to offer a vast selection of ethical and sustainable diamonds that are identical to natural diamonds in every way.

Legit Lab Grown Diamond Retailers Online

Looking to purchase lab grown diamonds online, but not sure where to start? With so many options out there, it can be overwhelming to choose a reputable retailer. However, there are some online diamond retailers that have earned a stamp of approval and are known for selling certified, legitimate lab grown diamonds.

If you’re in the market for lab grown diamonds, consider checking out the following online retailers:

Brilliant Earth: This company is committed to ethical and environmentally friendly practices, offering a range of lab grown diamond options. They also offer a lifetime warranty and a 30-day return policy.

James Allen: With over 200,000 lab grown diamonds available, James Allen is a popular choice for online diamond shopping. They also offer 360-degree videos of each diamond, making it easier to see the diamond’s quality before making a purchase.

Clean Origin: This company specializes in lab grown diamonds and offers a wide range of options, including fancy colored diamonds. They also offer a lifetime warranty and a 100-day return policy.

When it comes to buying lab grown diamonds online, it’s important to do your research and choose a reputable retailer. By selecting a company with a strong reputation and good reviews, you can ensure that you’re getting a high-quality, certified diamond for your engagement ring or other jewelry purchase.


Lab-grown diamonds have gained tremendous popularity in recent years as they possess similar physical and optical characteristics to mined diamonds, and are also produced through an ethical and environmentally friendly process. Two methods are used to create lab-grown diamonds: High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD).

Although lab-grown diamonds may lack the historical or sentimental value of mined diamonds, they provide a sustainable and cost-effective alternative for consumers seeking to own a diamond. As a result, they have become increasingly popular.

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