The Science Behind Lab Grown Diamonds: What, How, When, Why

The scientific process behind lab grown diamonds is nothing less than magical. The process of growing diamonds in the laboratory involves a combination of scientific processes that mimic natural processes, and craftsmanship.

The journey from a seed to a polished diamond is a complex one, which involves several calculated and careful steps. The lab diamond manufacturing process involves expertise of various kinds. From the selection of a good quality diamond seed to controlling its growth to polishing and grading, the process involves expertise at all stages.

This blog will guide you through the science behind lab diamonds, the growth process, various components, and more.

Let’s get started!

Factors Involved in Growing Laboratory Diamonds

Some of the key factors involved in creating man-made diamonds are the material, the process, the equipment, among others. Let’s look at some of these factors in detail.

The Diamond Seed

The first thing required to grow engineered diamonds is a diamond seed crystal. Seeds are nothing but crushed diamond powder. The seed is made up of carbon and may also contain other chemicals, such as nitrogen. However, its main component is carbon.

The crystal seeds provide a base for the growth of diamonds. The seeds go through two processes for the creation of lab grown diamonds — High Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD). Both these processes are different and engage differently with the diamond seed.

The seed either goes through gases or high temperature and pressure that leads to the growth of layers of carbon atoms. The lab diamond keeps growing bigger based on the atomic patterns of the seed crystal.

CVD vs. HPHT: The Two Primary Methods of Diamond Synthesis

The two processes used to create lab grown diamonds are HPHT and CVD. Let’s go through these processes in detail.

1. HPHT (High Pressure High Temperature)

• Step 1: Selection of a diamond seed crystal

The process begins with the selection of a small, high-quality single-crystal carbon substrate – a diamond seed. The better the quality of the diamond seed, the more superior the final lab grown diamond.

• Step 2: Placing the diamond seed into the growth chamber

The diamond seed is placed along with other elements inside the growth chamber, which is a high-pressure equipment. In the HPHT process, there are two press designs: the Belt Press and the Cubic Press.

• Step 3: Application of high pressure and high temperature

Once inside the chamber, the press begins the process of applying pressure and temperature. The extreme pressure and temperature lead to the process of carbon diffusion, leading to diamond crystallization. The process is controlled for weeks and months until the rough diamond is formed.

• Step 4: Post-growth processes

Once the rough diamond is fully grown, the process of cooling and depressurization begins. The rough diamond is then mechanically and chemically separated from the chamber. Once extracted, the rough diamond goes through the process of polishing, and grading.

2. CVD (Chemical Vapor Deposition)

• Step 1: Selection of the diamond seed and preparation of the chamber

The first step is the selection of a high-purity diamond seed plate. The seed quality is critical because any contamination could get amplified in the CVD growth process.

• Step 2: Placing the seed in the chamber

The seed is mounted in a vacuum-sealed CVD reactor. There are two types of reactors – Microwave Plasma Chemical Vapor Deposition and Hot Filament CVD.

• Step 3: Introduction of growth gasses in the chamber

A combination of glasses, including methane and hydrogen are introduced into the reactor chamber. The flow is controlled. Other gasses are added depending on the color required.

• Step 4: Gas activation and carbon deposition 

A combination involving high-power microwave sources, temperatures, and atomic hydrogen lead to the growth process. The process decomposes methane, creating reactions, leading to the formation of the diamond, which can take a few weeks to months.

• Step 5: Post-growth HPHT annealing 

CVD diamonds often display brown or grey tint caused by the process. This is eliminated using the post-growth HPHT annealing treatment. The diamonds are then cut, polished, and graded.

When were lab grown diamonds first created?

The origin of lab grown diamonds or synthetic diamonds can be traced back to 1954 when General Electric (GE) scientists created a diamond in the laboratory using the High Pressure High Temperature (HPHT) method. The earliest lab diamonds were mainly used for industrial purposes for cutting and grinding tools. Gem-quality lab grown diamonds were introduced to the market by the 1970s. And by the early 2000, the industry saw advancements in the process of creating diamonds, leading to better quality.

How are lab grown diamonds different from natural diamonds?

What are lab grown diamonds made of?

Lab diamonds are made of the same materials as mined diamonds. The materials include pure carbon atoms. This leads to the hardness of lab diamonds, which is 10 on the Mohs scale. The two methods used in creating lab diamonds are HPHT and CVD. While the HPHT process involves pressure and temperature, the CVD process involves various gasses. Both lab grown diamonds and natural diamonds have the same chemical, physical, and optical properties, and both are real diamonds, graded with the same standards.

On Conclusion

Creating the best man-made diamonds is science but it is also an art. Lab grown diamonds are created using advanced technology and scientific methods. The industry is continuously experimenting with new methods, technology, and more to expand the field of lab diamonds. If you’re looking for lab grown diamonds or to learn more about them, check out Grown Diamond Corporation to know more about these scientific wonders.