How Lab-Grown Diamonds Are Made

Home / Publications / Online Library / How Lab-Grown Diamonds Are Made

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.