Chemical Vapor Deposition can be described as growing diamonds from carbon-containing gas.
CVD process starts from the following: we put a diamond plate inside the vacuum chamber and heat this plate up to 800 ⁰C. Then the chamber is filled with carbon-rich gas (usually methane) which is also heated up to 3000 ⁰C with a microwave beam. It is done in order to break molecular bonds and release carbon atoms which are then deposited onto the diamond plate. Slowly but surely the diamond grows upwards (it's length and width are limited by the size of the plate). CVD requires 1-4 weeks from start to finish (depending on required weight).
Chemical Vapor Deposition, or CVD, is a process used to create gem-grade diamonds as well as optics and semiconductors. The CVD process uses ultra-pure carbon-rich gasses in a controlled chamber. Carbon-based gasses, such as methane, are heated until they break apart allowing the carbon atoms within the gas to separate. These tiny carbon atoms fall onto a diamond substrate and build up layers resulting in a rough diamond crystal. This process takes between six to ten weeks and yields gem-grade Type IIa diamonds.