How Are Lab-Grown Diamonds Created?

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How Are Lab-Grown Diamonds Created?

Published: 17 May 2022

Shining, shimmering, and splendid, diamonds are the best gemstones you can have in an engagement ring. Its beauty, however, comes at a cost. While the overall price will depend on factors like carat, colour, cut, and clarity, the most beautiful diamonds will cost a lot. Nonetheless, if you are on a budget, you can find affordable diamonds. These are not natural. Instead, these are lab-created diamonds. Read on and learn more about lab-grown diamonds, specifically how they come to life.

The Process for Creating Lab-Grown Diamonds

Planning the perfect proposal? Shopping for the best wedding jewellery? Looking for ways to save money? There’s one thing that you should learn about—lab-grown diamonds. They are beautiful and affordable. Creating these diamonds is a complex process, making sure that they resemble their natural counterparts.

Chemical-Vapour Deposition (CVD) Method

The CVD method for making lab-created diamonds is a recent technique that grows diamonds from a hydrocarbon gas mixture. It started in the 1980s and continues to be popular these days because it is an affordable procedure. Hence, makers of diamonds through such a process can offer them for cheap. 1. The process starts with the selection of a thin diamond slice. It is often 300 microns thick with a size of 10x10mm. In most cases, it is taken from an existing synthetic diamond. 2. It is then cleaned. This is an important procedure as it will ensure a more seamless stone. Otherwise, there will be lots of inclusions. 3. The slice of the diamond will then be placed inside a chamber. The chamber is sealed, which will prevent the infiltration of other gases. 4. A carbon-rich gas fills the chamber. Once filled, it will be heated at extreme temperatures. 5. To speed up the process of creating lab diamonds, nitrogen is added to the mix. Some labs, however, will skip this process and would rather be patient as it can make the diamond yellowish. 6. The gas in the chamber will break down and coat the diamond slice. It will bond on the surface, which will make the diamond bigger. 7. For a few weeks, the gas will continuously fill the chamber. It will also continually coat the slice of diamond to increase its size, which is technically known as a carat. 8. Once done, the result is a rough diamond, which is often square. 9. The lab will now use laser techniques and other polishing procedures to turn the diamond into its desired shape. This will also help eliminate imperfections. 10. The diamonds will now undergo certification. Graders will evaluate the diamond based on certain parameters.


High-Pressure High Temperature (HPHT) Method

The HPHT method is the traditional option for creating lab-grown diamonds, which started in the 1950s. It is used even in mined diamonds, specifically for enhancing colour and clarity. It replicates the earth’s temperature and pressure to create diamonds in a controlled environment. The main difference is that instead of taking years for diamonds to form, they will be ready within a few weeks. 1. The carbon is placed in a containment cube. In most instances, such is derived from an already existing lab-created diamond. 2. The cube will then be pressed. The goal of this procedure is to mimic the same pressure that a natural diamond will have to go through on the surface of the Earth. 3. Electric pulses are used for heating the diamond. Similar to recreating the earth’s pressure, it will also recreate the heat underground. 4. Within a few weeks or one month, the lab will have a rough diamond. It is cut and polished to improve the overall appearance, making the stone look like mined diamonds. 5. The last step is diamond certification. It will certify that the diamond is created in a lab while also assessing colour, carat, cut, and clarity.


Which Is Better, CVD or HPHT?

Now that you have a rough idea of how lab-grown diamonds are created, you are probably wondering—which one is better? For the uninitiated, it is almost impossible to tell the difference. Unless you ask the seller directly or look at the diamond’s information, it is challenging to identify the specific procedure in which the stone was grown. The main difference lies in the diamond growth patterns. From afar, you won’t be able to notice such. Nonetheless, upon closer inspection by someone who has a trained eye, it is possible to detect the difference. The shape of an HPHT diamond is a cuboctahedron. It will have 14 growth directions. On the other hand, CVD diamond is cubic in terms of shape. It only has a single growth direction. Another common difference is that HPHT diamonds will have geometric colour zoning and a CVD diamond will have even colour distribution. With recent technological advances, however, it became easier for diamond makers to manipulate colours. Through the CVD method, the result is a Type IIA diamond. It is considered the most chemically pure diamond as it does not have boron and nitrogen impurities, which are present in HPHT diamonds. In terms of sustainability, they are almost the same. This is where things get interesting. A lot of people may think that lab diamonds are sustainable. Nonetheless, it may not necessarily be the case. It requires a lot of energy to manufacture them, which can result in greenhouse gas emissions that can harm the environment. At the end of the day, it is almost impossible to tell which method is better unless you look at the specific stone. They are both great. The overall quality and appearance will depend not on the chosen process. The best thing to do is to pick one from a reputable seller.


In summary, lab-grown diamonds are created through two main processes – Chemical Vapour Deposition and High-Pressure High-Temperature methods. They are both made in a controlled environment that mimics the natural conditions in which mined diamonds grow. It is not a question of which process was used, but it all boils down to the quality of the diamond the maker produces.