Each laboratory-created diamond is grown by placing a diamond ‘seed’ into a chamber of heat and pressure. This chamber mimics the natural growing process. Crystallization occurs allowing the lab-grown diamond to mature within six to ten weeks. It is then cut, polished and graded by the same world-renowned labs that certify earth-mined diamonds. The following technique are most commonly used by laboratories:
CHEMICAL VAPOR DEPOSITION (CVD)
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.In recent years, CVD research has gained popularity and now modified versions of CVD are being used. These processes differ in the means by which chemical reactions are initiated. Some of these variations include:
Low-pressure CVD (LPCVD) Ultrahigh vacuum CVD (UHVCVD)
Plasma-enhanced chemical vapor deposition (PECVD)
Microwave Plasma Vapor Deposition (MPCVD)
Ultrahigh vacuum CVD (UHVCVD)
It takes approximately 2-3 weeks to grow a rough diamond that will yield a 1ct polished gemstone.
Cutting and polishing may take another 4-8 weeks. The longer a rough is left in the reactor, the greater chance of developing more inclusions or cracks.