What are synthetic diamonds made of?

Two methods are used to create synthetic diamonds in the laboratory setting — chemical vapour deposition (CVD) and high-pressure, high-temperature (HPHT). Regardless which process is used, these laboratory-grown diamonds are composed of the exact same crystallized isotropic 3D pure carbon, the same as mined diamonds.

What is a synthetic diamond?

Synthetic diamonds are often referred to as cultured or cultivated diamonds, and they are authentic diamonds that have been created in a laboratory as opposed to being created by a geological process. Synthetic diamonds are not to be confused with simulated diamonds or imitation diamonds which are really just crystals such as cubic zirconia — synthetic diamonds are 100 percent real and identical to mined diamonds in terms of physical and chemical properties.

Two processes used to create synthetic diamonds

Currently, in the UK, two methods exist for creating cultivated diamonds:

  • High-Pressure, High-Temperature (HPHT): This process is the one that is most like how diamonds are created underground. In this method, a machine is used that mimics the conditions found deep within the Earth. Carbon is heated to more than 2000℃ and pressures in excess of 60,000 atmospheres are applied to create a diamond from the pure carbon sample.
  • Chemical-Vapor Deposition (CVD): This method does not require the pressurized conditions used in HPHT. Instead, a pure carbon sample or a tiny piece of diamond is placed inside a machine within a chamber. Natural gas is added to the chamber and zapped with microwaves. As a result, carbon atoms fall and deposit on the sample and a diamond is grown.