How Do They Grow Diamonds in the Lab?

Lab grown and mined diamonds are chemically the same.

Gemologists often refer to lab-grown diamonds as synthetic, since the diamonds did not develop naturally. But, lab grown diamonds are chemically identical to mined diamonds as long as the growing process is carefully controlled.

Chemical Vapor Deposition

The chemical vapor deposition method of growing diamonds starts with placing small, flawless, diamond seeds in a vacuum chamber. A cloud of carbon gas is then released into the chamber and heated to 1,800 degrees Fahrenheit. Carbon crystallizes onto the diamond seeds creating a larger diamond.

High Pressure High Temperature

The high pressure high temperature method of creating diamonds begins with placing diamond seeds and a graphite disk into a metal container. The container is heated to between 1,350 degrees and 1,500 degrees Fahrenheit and extreme pressure is applied. Carbon precipitates onto the diamond seed from the graphite disk and forms a larger diamond.

Lab Grown and Mined Diamonds

Ultraviolet radiation produces different results on lab-grown and natural diamonds. Lab-grown diamonds tend to form a different structure than mined diamonds. Colored diamonds are rare in the natural world, yet common in lab-grown diamonds.

References

• Smithsonian Magazine: Diamonds on Demand
• Gemological Institute of America: Spring 2008 First CVD Synthetic Diamond Submitted