Diamonds are forever... how to make the perfect gem in a science lab

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Most “gem quality” diamonds - like those used by Nightingale - are grown using a process known as chemical vapour deposition (CVD).

Here is the process in more detail...

1: Hydrocarbon gas and hydrogen are mixed at high temperatures in a low-pressure vacuum chamber. Some molecular hydrogen is converted into atomic hydrogen.

2: A small substrate or “seed” of diamond is introduced into the gas mixture at a temperature between 900 and 1200°C.

3: Hydrogen-carbon species travels across the surface of the “seed” until it finds an available carbon atom to attach itself to, increasing the thickness of the seeded growth by one atom.

4: Process repeats itself endlessly, with the diamond growing three dimensionally while maintaining its original crystal structure.

5: When the diamond created reaches its optimum size, it is cut and polished in the same way as a naturally occurring diamond.

How one Yorkshire jeweller is turning to the lab for his diamond prize

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