what is a lab-grown diamond?

A lab-grown diamond is a real diamond, grown in a controlled laboratory environment rather than mined from the earth.

This is achieved by replicating the natural process that forms diamonds deep in the earth. Lab-grown diamonds are composed of pure carbon, and share identical chemical, physical, and optical properties to those of mined diamonds. The only difference between the two is their origin.

The Luise Ring — Oval and Emerald Toi Et Moi Lab-Grown Diamond Engagement Ring in Yellow Gold | The Jewel Concierge

how are lab-grown diamonds made?

There are two main methods to create lab-grown diamonds; High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD). Both begin with a tiny diamond seed and build new crystal, carbon atom by carbon atom.

Assortment of lab-grown diamonds laid on white parchment paper along with diamond tweezers on a soft luxurious grey background - The Jewel Concierge

High Pressure High Temperature (HPHT)

In the HPHT method, a small diamond seed is placed inside a specialised press designed to generate extreme temperatures and pressures. A carbon source surrounds the seed and, under these intense conditions, begins to break down and reform around it. Over time, carbon atoms organise into a solid crystal lattice, gradually building a new diamond.

Lab-grown diamonds placed on tweezers, resting on a light blue soft cushion against a warm champagne background | The Jewel Concierge

Chemical Vapour Deposition (CVD)

With CVD, the diamond seed is placed inside a vacuum chamber filled with a carbon-rich gas. When the gas is energised, carbon atoms separate and settle gently onto the surface of the seed. This steady layering continues over several weeks, forming a diamond with the same brilliance and durability as one that formed beneath the earth’s surface. 

Both methods take weeks, compared to millions of years for natural diamonds. The result is diamonds that are indistinguishable from mined ones without the use of specialised equipment. Once grown, every diamond is cut, polished and graded exactly as a mined stone would be, assessed against the same 4Cs and certified by the same independent institutes.

For a full comparison of lab-grown and mined diamonds, including quality, value, environmental impact and buying tips, read our complete lab-grown diamond guide. Ready to see them set? Explore our lab-grown diamond engagement ring collection.