Diamonds are composed of pure carbon atoms arranged in an organized matrix. While geologists cannot say for certain how diamonds formed in the mantle of the Earth long ago, it is known that carbon deep within the Earth was exposed to extreme heat and pressure which turned it into diamonds.
Over the years, these diamonds were pushed towards the Earth’s surface where they cooled. People have been digging up and collecting these diamonds for centuries.
Even though geologists cannot decide exactly how natural diamonds were formed — thanks to modern-day diamond growing equipment, they don’t have to!
Authentic diamonds are now grown in laboratories by means of two distinct processes. One process is referred to as high-pressure, high-temperature (HPHT) and uses an HPHT machine that creates an environment of extremely high pressures in excess of 60,000 atmospheres and temperatures in excess of 2000°C in order to mimic the natural process.
A sample of carbon is placed inside this machine and exposed to the artificial environment which causes it to grow it into a diamond over a period of time that lasts anywhere from a few weeks to a few months.
Another process used to grow diamonds is referred to as chemical vapour deposition (CVD).
In this process, a small sample of carbon is placed inside a depressurized chamber of a machine. Next, natural gas is added and heated by microwave beams. As a result, carbon atoms drop down and collect on top of the sample — which forms a diamond. The CVD process creates a diamond more quickly, in as little as 24-72 hours.