In nature, diamonds are formed deep in the earth’s crust where temperatures and pressure are very high. These diamonds only become available for mining when rare volcanoes erupt and bring the diamonds within 100 feet of the surface.
The effort to mimic this process in nature is not new. Scientist began a rudimentary version of recreating diamonds beginning in 1954 and other gemstones, such as rubies, were replicated well before that. We have come a long way since those early days and we are now able to create diamonds that cannot be differentiated from natural diamonds with the naked eye.
While there are several variations for each of these processes, lab-grown diamonds are produced in one of two main ways, Chemical Vapor Deposition (CVD) and High Pressure High Temperature (HPHT) manufacturing.
When using the HPHT process, pure carbon and a tiny piece of diamond referred to as a starter seed, are placed in a high pressure, high temperature chamber. As the carbon is heated, it melts around the starter seed and a diamond is created. At this time, the HPHT process makes it possible to create much larger diamonds than the CVD process.
A diamond made using CVD begins with a narrow slice of diamond seed and places it in a sealed chamber. By filling the chamber with hydrocarbon gas mixtures and ionizing them into plasma using lasers, microwaves and other techniques, the molecular bonds in the gases are broken and the pure carbon sticks to the diamond seed. This process does not require high pressure and the temperatures, while still high are nowhere near what is required for HPHT.