Synthetic diamonds grown in a lab are virtually identical to natural diamonds, but that’s where the similarities end. In fact, there are two distinctive methods used to grow synthetic diamonds.
The traditional diamond growth method was developed in the 1950s. It involves the use of expensive equipment creating very high-pressures and high-temperatures (referred to as HPHT). This process takes about 5 days to grow a 1-carat crystal that, due to the unique laboratory growth conditions, forms a very distinctive shape. The most common colors for these synthetic diamonds are yellow and brownish yellow, though others such as blue, pink, red and green are also possible.
But over the past decade, a new method for growing diamonds has emerged: chemical vapor deposition, or CVD. Instead of using high-pressure machines, diamond crystals grow from a gas at very low pressures in a vacuum chamber. Only a few companies have the skill to use this process, and most diamond crystals are less than .5 carats and form a tabular shape, which differs from that of natural diamonds. In contrast to the older HPHT method, this method can grow colorless crystals, while making colors such as blue, yellow, pink, red and green possible as well.
[Note: in both processes, blue is due to the presence of boron in the diamond, while the other colors are the result of a post-growth treatment process involving radiation exposure and sometimes heating]
As synthetic diamond production continues to rise, it’s becoming an even greater necessity to know exactly what you’re buying. To properly identify the differences between a synthetic diamond and a natural one, be sure to receive a professional lab evaluation.