Diamond is one of the most beautiful and unique stones. However, they are mined in the ground, which is not great for the environment. As a way to reduce inflicting more environmental harm, lab-grown diamonds were introduced and have been gaining popularity in the past years. While they don’t grow naturally on the Earth, they are still made of the same minerals and the process mimics that of the natural one. They are composed of the same carbon molecules as their naturally occurring counterparts.
How are lab-grown diamonds made?
A diamond is made up of carbon atoms. Carbon is crushed up, heated up, and put under intense pressure. Despite knowing the process, it still begs the question, what is a lab-grown diamond? Lab-grown diamonds are diamonds that are grown in labs. They’re scientifically identical to real diamonds, except that they’ve grown in controlled environments, and not mined from the Earth.
There are a few ways to determine whether a diamond is a lab-grown diamond. One way is to take a thermal imager to it. Natural diamonds have a unique thermal signature that lab-grown diamonds will not have. Knowing the science behind lab-grown diamonds is important because many people still doubt the authenticity of such gems.
Methods to grow lab diamonds
There are generally three methods used for lab-grown diamonds. It includes:
- Carbon Vapor Deposition (CVD).
- High Pressure and High Temperature (HPHT).
- Plasma-Assisted Chemical Vapor Deposition (PACVD).
a. Carbon Vapor Deposition (CVD)
CVD is one of the most popular diamond growth techniques. It involves growing diamonds from the vapor phase by feeding a hydrocarbon gas mixture into a microwave plasma. The feedstock is a mixture of ethylene and hydrogen in a ratio of 2:1. The hydrocarbon gas is fed into microwave plasma in a quartz tube between 1,000 and 4,000 degrees Celsius.
The gas will break down into carbon and hydrogen elements, which will then be deposited onto the silicon carbide substrate. The proteins are responsible for diamonds’ growth. They are embedded in the substrate, then placed on top of a hot spot. The combination of the proteins and the high temperature causes the diamond to form. The cost of using this process is much less than other processes.
CVD can provide more diamonds in a shorter amount of time than other forms of creation. Not only that, but the energy needed for this process is also low compared to other methods, which means that the costs for production are consistently reduced. With the number of diamonds produced by this method and the energy requirement, it makes sense why CVD is such a hot topic.
b. High Pressure and High Temperature (HPHT)
The diamond creation process has been widely disputed over the years, with a different process being theorized each time. Theories have included a high-pressure, high-temperature (HPHT) process to a purely environmental one, suggesting that they could be formed from carbon-rich environments. First, you need to take carbon and turn it into graphite. Next, you need to take this graphite and place it into an oven with a temperature of around 1,800 degrees Fahrenheit. Next, you’ll need to apply pressure to it.
The stove heats the mixture, which spins rapidly in a “diamond anvil cell chamber”. The mixture becomes a liquid when it reaches a very high temperature and pressure. The sparkles we see during the creation of a diamond are the fingerprint of the liquid. The fluid is compressed between two diamonds with great pressure. The diamonds are removed when the liquid becomes solid, and the finished product is a diamond.
c. Plasma-Assisted Chemical Vapor Deposition (PACVD)
Plasma-Assisted Chemical Vapor Deposition (PACVD) is a process by which a carbon source is sent through a tube usually made of copper and oxygen suspended over a vacuum. The carbon heats to the point where it becomes plasma, the fourth state of matter. The plasma is then directed towards a thin tin film on a substrate. The crystal growth process starts when the liquid is heated up to the temperature.
A diamond crystal is created when the carbon atoms are combined. The pressure makes the crystal grow inside the carbon liquid. The chemicals added to the process help speed up the process. The process of getting a rough diamond starts after the crystal is formed. After the growth of the diamond, the process goes to the polishing process. The rough diamond is cut and polished. Then, it is cut into the size. It is fixed into a setting and made into a ring.
Differences between lab-grown diamonds and natural-occurring diamonds
| Lab-grown diamond | Natural-occurring diamond |
| Lab-grown diamonds are made through a chemical process that is duplicated in a lab. | Natural diamonds are formed in the Earth’s center, where extremely high temperatures and pressures exist. |
| Diamonds grown in a lab are purer than naturally occurring diamonds because you can change their size and color according to your needs. | Every natural diamond is unique, so you cannot change its size and color. |
| Lab-grown diamonds are often less expensive. | Natural-occurring diamonds are more expensive because they are mined from the Earth. |
Final thoughts
Diamonds are one of the hardest materials on Earth. They can be difficult to cut and polish when mined from the ground. For these reasons, lab-grown diamonds are quickly gaining popularity. The science behind lab-grown diamonds is a very interesting thing to look into. It’s a fascinating process involving precise steps and materials and a scientific understanding of the diamond business. It’s all about the right approach and the right materials.
The process begins with using the right material, a certain type of carbon, in a vacuum. The vacuum removes any oxygen and creates a pure carbon environment. Then, the carbon is heated up to extreme temperatures. Lab-grown diamonds can be in every size and have minor imperfections, but they are also much cheaper to purchase. These diamonds are also grown organically, so they are environmentally friendly.
