Columnar growth pattern in CVD synthetic diamond – not seen in natural stones
Synthetic diamonds are quickly becoming a regular occurrence in the jewellery industry. As technology is becoming more advanced, synthetic diamonds are now being produced in sizes of up to 3 carats. To the surprise of many, diamond company DeBeers, previously only trading in natural diamonds, now has a subsidiary company supplying a synthetic diamond jewellery range to the world.
It is essential the jewellery industry is educated about determining the difference between these types of diamonds, to ensure clients are not only educated about their purchases but are getting what they pay for and jewellery is valued accordingly.
What is the difference between natural and synthetic diamonds?
To the untrained eye, synthetic diamonds can look as real as natural ones, creating a cause for concern. The prices of synthetics are less than their natural counterparts, and predictions of synthetic prices dropping have been made as the technology becomes more advanced over time.
To produce natural diamonds takes millions of years. The vast majority of natural diamonds are low quality ‘industrial grade’ crystals. Specific temperatures, pressure and a suitable chemical and geological environment are required to ensure that the diamonds are of gem quality.
By comparison, to create a piece of synthetic rough by machine takes approximately 2–3 weeks. Synthetic diamonds are made by machine in two ways: one by CVD (chemical vapour deposition) in a vacuum using a gas phase carbon or by HTHP (high temperature high pressure) using carbon and mimicking the environment in which natural diamonds form with pressure and heat. All are technically a diamond (made from the same components as the natural).
With an interest in these techniques, Kylie recently partook in an advanced diamond grading course where she learnt the different ways to distinguish between natural and synthetics.
How to tell between a natural and synthetic diamond
CVD and HTHP synthetics display different graining patterns to naturals, as seen here, as well as different reactions to ultraviolet light and colour or growth zoning. Separating such stones from natural diamonds requires the use of advanced spectroscopic techniques and certain
gemmological equipment. After attending a workshop on detection of synthetics, Greg and Peter decided to invest in a digital spectrometer for our gem laboratory so that we could better protect our customers.
We can sadly no longer assume a diamond is of natural origin.