Lab-grown diamonds are created using two methods: high pressure, high temperature (HPHT) and chemical vapor deposition (CVD). The HPHT method involves a small diamond seed being placed in a chamber with a mixture of gases and heated to high temperatures and placed under immense pressure. The CVD method involves using a plasma torch to vaporize a carbon-containing gas, such as methane, and the carbon atoms deposit onto a substrate forming a diamond crystal.