The Chemical Vapor Deposition (CVD) method creates lab-grown diamonds in a more moderate, highly controlled environment, using a slower growth cycle that typically takes about 6 to 12 weeks. A thin slice of diamond—known as a diamond seed—is placed inside a sealed growth chamber and heated to high temperatures, sometimes reaching around 1,500°F.
Next, gases such as hydrogen and methane are introduced into the chamber. These gases are energized (ionized) to form a plasma that breaks the molecules apart and releases pure carbon atoms. Those carbon atoms then settle onto the diamond seed and bond to its crystal structure, building the diamond layer by layer.
Over time, this steady accumulation of carbon forms a single, larger diamond crystal that is removed as a rough stone and then cut and polished just like a natural diamond. The final growth time depends on the desired size, the growth rate used, and the quality targets for the finished diamond.