Various articles and links pertaining to various forms of the plasma-CVD process:

2008:

Hindu Business Line - Scientists on track to mass-produce synthetic diamonds

2005:

Advanced Materials - Diamonds grown 100 times faster via plasma

Summary:  "A microwave plasma method for growing synthetic diamond gemstones as perfect as those found in nature has reportedly been developed by the University of Alabama at Birmingham and the Carnegie Institution, Washington, D.C. The technology is based on microwave plasma, which makes it possible to produce gemstones 100 to 200 times faster than conventional methods."

Electronics Weekly - Grow Diamonds 'in a few days'

Advanced Ceramics - Plasma Process grows diamond at high speed

JCK - University claims 'better, faster' synthetic diamonds

2004:

Electronics Weekly - Scientists grow synthetic diamonds harder than natural stones

Science Daily - Large diamonds made from gas are the hardest yet