A lab-grown diamond is a gem that is identical in chemical composition to a mined diamond, but which was grown in a laboratory environment, rather than mined from the earth. Lab-grown diamonds are “real” diamonds in every way! In fact, in 2018 the Federal Trade Commission (FTC) ruled that lab-grown diamonds were “natural” diamonds and can be referred to as such.

There are two distinct manufacturing processes used to grow diamonds in a lab: HPHT and CVD.

HPHT (High Pressure High Temperature) is the older of the two processes, around since the 1950s. In HPHT, a small amount of graphite is subjected to extreme temperatures and pressures, which replicates the extreme heat and pressure conditions deep inside the earth that cause diamonds to form.

The second and more recent method is termed CVD (Chemical Vapor Deposition). This is a vacuum deposition method that is often used in the semiconductor industry to produce thin films. The diamond CVD technique was first investigated over 30 years ago, but it is only within the last decade that the technology had improved to the point where very high quality diamond can be formed.

In CVD, a thin slice of diamond – called a seed – is placed in a sealed chamber and heated to a very high temperature. After the chamber is heated, a carbon-rich gas mixture is introduced into the chamber, and those gases are ionized into plasma. The chemistry created in the plasma along with the high sample temperature results in growth of high-quality diamond.