Making a Diamond in the Lab
There are two primary ways in which lab-grown diamonds are grown:
High Pressure/High Temperature (HPHT)
Used since the 1950’s, this traditional technique subjects a diamond seed crystal to high pressure and high temperature to initiate growth of a diamond. Initially the technology primarily produced yellow or brownish yellow diamonds more suited for industrial applications. In recent years, the technology has evolved to produce colorless diamonds.
Chemical Vapor Deposition (CVD)
A tiny diamond “seed” is placed in a vacuum chamber and lab-quality carbon gases are used to grow crystals on the seed. Requiring less expensive equipment than HPHT diamond production, the technique has been fine-tuned within the last decade to produce colorless gems. Because the stones are grown in a vacuum, there are usually no inclusions in the stones.
While many diamond screening devices can check for both CVD and HPHT diamonds, not all can so be sure to check with a device’s manufacturer.