CVD Diamonds.

A CVD diamond is a grown in a vacuum chamber. First, a diamond seed—a tiny splinter of natural diamond—is placed in the chamber. Second, the chamber is filled with carbon-rich gas. Last, the temperature inside the chamber is raised to over 800 degrees Celsius. This extreme temperature causes the gas to change to plasma, which releases carbon pieces. Over a few weeks, these pieces attach themselves to the diamond seed, eventually forming the diamond.