It is widely acknowledged that diamonds are the hardest known natural substance on Earth. They were formed in the Earth’s crust millions of years ago through a combination of very high temperatures and pressures over a sustained length of time. They are very rare, hard to come by and consequently precious. So can they really create diamonds in a lab?

On the face of it, this seems impossible. After all, the time taken for a diamond to form would seem to make this a non starter. However, the demand for diamonds continues to increase. The retail jewelry market keeps the prices of natural diamonds high, even driving them up as more and more people believe that natural diamond jewelry is their birthright.

However, the gem industry is not the only outlet for diamonds and high prices have made in necessary for industrial users, such as cutting tool manufacturers to seek alternative diamond sources.

In fact scientists found a way to create diamonds in a lab over two decades ago. And although the synthetic diamonds are produced under high temperatures and pressures, they are formed in only a matter of a few days rather than millennia! The resultant crystals are chemically identical to natural diamond, although they are distinguishable from it by a distinctive growth pattern visible under close examination using hi-tech instruments.

So how is it done?

In fact there are two ways. The first is called the High Pressure High Temperature (HPHT) method, which is used by all diamond manufacturers, and the second is the Chemical Vapor Method (CVM).

HPHT method mimics the natural processes which go to form diamond. In the natural process, the high temperatures and pressures cause carbon to change into its crystalline state and form diamond. To shorten the production time, iron or cobalt catalysts are used, and a molten graphite carbon source is exposed to excessive pressures of 55,000 atmospheres and pressures of 1400 degrees centigrade. A tiny seed diamond is added to the mix to act as a growth template for the developing diamond.

In CVM, high temperatures and pressures are again used. However, the carbon source in this case is a gaseous carbon compound which is split into its elemental components. The gaseous carbon showers over a seed diamond template, growing it in the process. Large diamonds cannot so far be grown using CVM.

Whilst both methods do produce synthetic diamonds that are identical to natural diamonds, neither process works without the presence of a natural seed diamond to start the crystalline growth. So it is more accurate to say that synthetic diamonds can be grown in a laboratory, rather than created in one.

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