Press Record.

http://www.cbsnews.com/stories/2004/05/10/60II/main616666.shtml
In a warehouse in Florida, and another one near Boston, real diamonds are being made in labs. The technique still hasn’t been perfected, but it’s a big step. And what used to take thousands of years to create can now happen in a matter of days, and at a fraction of the price.

http://pubs.acs.org/cen/coverstory/8205/8205diamonds.html
Within each chamber, a tiny sliver of natural diamond is bathed in a molten solution of graphite and a proprietary metal-based catalyst at approximately 1,500 °C and 58,000 atm of pressure. Slowly, carbon precipitates onto the diamond seed crystal. A gem-quality, 2.8-carat rough yellow diamond grows in just under three-and-a-half days.