How Are Lab-Grown Diamonds Made?

A lab-grown diamond is born from an extraordinary fusion of physics, chemistry, and precision engineering. The process replicates the earth’s natural conditions in which diamonds are formed. It starts with a diamond seed. This is a tiny slice of an existing diamond. This seed is then placed inside a high-tech machine. They use one of two methods to grow it into a full gem over a few weeks.

Chemical Vapor Deposition (CVD)

The Chemical Vapor Deposition (CVD) method grows diamonds from carbon gas. First, an ultra-thin diamond seed is placed inside a sealed vacuum chamber. Next, the chamber is filled with carbon-rich methane gas and heated to extreme temperatures (900-1200°C). Finally, a microwave beam ionizes the gas into plasma, breaking its molecular bonds. This releases free carbon atoms, which rain down and bond to the seed layer by layer, crystallizing into a pure diamond over two to three weeks.

High Pressure High Temperature (HPHT)

The High Pressure High Temperature (HPHT) method replicates the extreme natural forces that form diamonds deep within the Earth. First, a small diamond seed is placed at the bottom of a heavy mechanical press. Next, carbon source material (like pure graphite) and a molten metal catalyst are loaded on top. Finally, machines apply extreme pressures (above 8,70,000 pounds per square inch) and intense heat (1300-1600°C). This melts the graphite, allowing the dissolved carbon to precipitate onto the seed and grow into a solid diamond crystal.

CVD vs HPHT

CVD	HPHT
Diamond seed crystals are placed in a diamond growth chamber which is filled with carbon-containing gas.	Diamond seed is placed in a specifically designed press.
The chamber is heated to about 900 - 1200°C.	Diamond seed is placed in a specifically designed press.
A microwave beam causes carbon to precipitate out of a plasma cloud and deposit onto a seed crystal.	The molten metal dissolves the high purity carbon source.

At Diamond Forest, we create diamonds using the Chemical Vapor Deposition (CVD) method