How are lab-grown diamonds made?
One of two processes is usually used to produce lab-grown diamonds: the CVD process (‘chemical vapour deposition’) or the HPHT process (‘high pressure high temperature’). Both processes are fundamentally different. Small, thin pieces of diamond known as ‘seeds’ are used as starting material for the CVD process. Larger stones can grow in the vacuum chamber under specific process conditions.
Lab-grown diamonds from Nevermined are grown exclusively using the CVD process.
The CVD process for lab-grown diamonds
Chemical vapour deposition is the more recent development of the two aforementioned processes in diamond production. In the CVD process, diamond seeds are placed in a chamber first of all. The seeds themselves are made of diamond which is also grown in the laboratory. The chamber, which is in a vacuum, is flooded with hydrogen. With the help of microwaves, energy is added to the hydrogen gas, igniting a plasma. In simplified terms, a plasma is a mixture of particles that can be thought of as a fourth state of matter (in addition to solid, liquid and gas).
Further gases such as methane and other additives are subsequently added to the plasma. In this process, the plasma heats the seed to a temperature of up to 1,000 °C. The high temperatures that arise in the chamber cause the chemical compounds of the added gases to break down. This releases carbon – the material diamonds are made of. The carbon particles now settle on the surface of the seeds and allow the diamond to grow, atom by atom, layer by layer. Diamond manufacturers are walking a physical tightrope here, as they have to carefully balance temperature, pressure and gas composition in their vacuum chamber. Fluctuations could affect the growth of the diamond, its clarity or its colour. If the complicated undertaking is successful, cuboid rough diamonds are created within a very short time. They are then processed and polished like natural specimens.
Laboratory diamond vs mine diamond
The diamond industry has faced serious challenges for many decades. Mining diamonds was and still is associated with social and ethical conflicts and serious environmental impacts. By producing diamonds in the laboratory, we at Nevermined can avoid all the conflicts associated with mining diamonds.