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How to Make Industrial Diamonds From Graphite

Because diamonds are so hard, they are often used in industry for cutting and drilling metal and other materials, including other diamonds. Some of these applications use natural diamonds that aren't large enough or beautiful enough to be used in jewelry. But others use synthetic diamonds made in a process called high pressure high temperature synthesis (HPHT) which replicates the conditions far underground where natural diamonds are formed. HPHT uses an expensive machine called the BARS apparatus to apply extremely high temperature and pressure to turn graphite into diamonds. This is not a project to try at home.

Things You'll Need

BARS apparatus
Powdered graphite
Tiny sliver of diamond

Instructions

- 1
  Place a tiny sliver of diamond, called a seed, in a capsule along with some graphite dust. The new diamond will grow around the seed.
- 2
  Place the capsule inside the BARS apparatus, also known as a split sphere. Tightly surround the capsule with six anvils. Together, the capsule and anvils are called the "cocoon."
- 3
  Place eight steel wedges on top of the cocoon and close the growth chamber. Surround the growth chamber with massive steel rings, called lock rings, which keep the growth chamber from blowing up under such massive pressure and temperature.
- 4
  Let the diamond grow for four days. During that time the temperature will rise to 2,732
  
  degrees F, melting the graphite, and 58,000 times normal atmospheric pressure will be applied. Under such great pressure, the graphite liquefies and the released carbon atoms start to align with the structure of the seed diamond, growing it.
- 5
  Remove the capsule from the machine and open it to see if it has grown or not. At the time of publication, this process is still hit-or-miss. Sometimes the result is a gorgeous gem-quality diamond. Sometimes it's a less beautiful diamond that is still valuable for its use in industry. And sometimes nothing happens at all.

Rocks & Minerals