A. What are synthetic diamonds
Diamonds are compared to coal sometimes because both have the basic component that is carbon. But the rest are totally different. In a very simple terms, heat and pressure(725,000 pounds per square inch) pushes the carbon atoms to fuse and then form diamonds.This process takes several thousand years and many miles beneath us deep within the Earth's crust.
Now scientist can re-create this process and over a few weeks we can make synthetic diamonds.The common process used is known as Chemical vapour deposition.
So, yes, diamonds are being produced commercially. These are referred to as Cultured or Lab diamonds.
B. How to differentiate?
The truth of the matter is that even trained/ experienced find it difficult to assess a diamond with regards to
being natural or synthetic
1. First, we need to be clear on the fact that Synthetic diamonds are not fake because they are diamonds, only the process and composition is different.
2.Flaws and clarity: Ironically, the term flawless natural diamonds can be applied to only few of the naturally mined ones. This is because, natural diamonds have flaws or inclusions within them, this can be modified or minimized in the synthetic creation process. So, a flawless diamond need not be the only criteria.
3.Scratch test: this is based on the hardness but can be destructive to the stone.
4. Thermal conductivity: diamonds are known to have a high thermal conductivity. This can be measured using
thermistor probes, but between synthetic vs natural, we need more advanced optical instruments, spectroscopy etc for proper assessment.
5.Commerical organisations use the services of professional techniques for testing diamonds.
a.One such example is the D-Screen device ( developed by HRD Antwerp and WTOCD).
b. Alpha diamond analyser (developed by HRD Antwerp and Bruker).
c. The Diamond Trading Company (DTC) of De Beers, has also two similar detection devices referred to as DiamondSure and DiamondView.
6. Cost: Again , this alone cannot be used to differentiate because some synthetic diamonds cost only 10% less than a natural diamond. As a general statement natural ones are around 20-40% more expensive than synthetic ones.
C.What is the practical way?
Given the above difficulties and complexity, we need to insist on a authenticity certificates from the manufacturer themselves. A flawless, crystal clear, coloured stone is often a synthetic one because a coloured (blue, red, yellow) natural diamond is very rare and hence very expensive.