Lab-grown diamonds are created using two main processes: High Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD). In the HPHT method, a small diamond seed is placed in carbon and subjected to extreme pressure and temperature to allow carbon atoms to form a larger diamond crystal around the seed. In the CVD method, a diamond seed is placed in a chamber filled with carbon-rich gas, where the carbon atoms accumulate on the seed and gradually form a diamond crystal. The process is then repeated until the desired carat weight is achieved. The exact process may vary depending on the specific manufacturer and equipment used.