Synthetic or Natural Diamonds?

Synthetic or Natural Diamonds?

Written by Alice Rochester on 30 November 2018

Research by the DPA says that for significant moments people still are very clear that they want natural diamonds to symbolise and tell their stories, but we are finding that we’re being asked about synthetic diamonds more than ever before, so we thought it would be interesting to put some information together to answer any queries.

What are they?

The word ‘diamond’ actually means a naturally formed gemstone and so some are saying that these synthetic stones shouldn’t be called diamond at all.  We have always been very careful about how we describe our gemstones and are aware of how misleading language can be. Some are calling them ‘lab created diamond’ but we have been advised to call them ‘synthetic diamonds’ for the moment because that is how we normally refer to other man made versions (e.g. synthetic sapphires).

Unlike diamond simulants like cubic zircon or synthetic moissanite which look similar to white diamonds but are chemically different, synthetic diamonds are real diamonds but they have been produced in a laboratory in the space of weeks or months rather than deep underground over the course of millions of years.  They have good clarity because there are no impurities present while the crystal is forming and they can be treated to change into different colours.

People are asking about them for three different reasons

1. They are concerned about the environmental and ethical consequences of mining for new stones

We’re always really pleased to have conversations about the ethics of our jewellery and are more than happy to work with both synthetic diamonds and natural mined stones. Both are interesting ethical options and we feel that it’s important to be able to offer both, depending on a customer’s own sense of what is right for them.

Many people are aware that mining is a dirty business and that huge amounts of rock need to be mined to get a small number of diamonds. We remind customers that creating crystals in a lab is more energy intensive than they expect - we can liken it to using FSC approved paper because it manages and protects woodlands, rather than using recycled paper which uses more energy in processing but requires no new trees to be cut down.  In fact, according to the DPA, the carbon footprint of a 1 carat synthetic diamond is equivalent to or sometimes greater than mining new stones.

Whilst synthetic stones are traceable and we know they are created in more wealthy countries where health and safety standards and employment laws are strict, we are very aware that this only tackles a small part of the ethical dilemma.  Mining supports millions of people all over the world who often have no other access to employment. As a company we believe in trying to support those at the bottom of the diamond supply chain who have no option other than to make a living by mining. We feel that if we were to only buy synthetic diamonds these people would have no other work and wouldn’t be able to support their families so we are currently working on a project to try to source traceable diamonds mined by artisans... This is going to be quite a journey.

2. They think they’re going to be significantly cheaper

Growing synthetic diamonds takes a huge amount of sustained energy over a course of weeks or months; the smallest fluctuation in heat or pressure could be disastrous for the growth of the crystal.  As such, larger stones in particular are sometimes more expensive than anticipated. The technology behind the creation of synthetic gemstones is improving rapidly, which means that (in contrast with natural diamonds whose value will increase) prices for synthetic stones are coming down. This is great for customers who don’t like the idea of new mining as it is making things more accessible; however it does mean their jewellery is likely to devalue. We actually have some synthetic diamonds that we bought last year that we have had to reduce in price as their value has gone down already. For those who would like to buy a fun piece of dress jewellery for themselves, this may be beneficial. Recently however the prices of synthetic diamonds have risen, yet this is the result of marketing hype so we predict that they will fall again. 

3. The person has a science background and likes the idea of crystal growth in a lab

Of course if somebody has a background in science then it’s lovely to know that we can help them to tell their story by sourcing a really special synthetic gemstone for them.


There are two main ways of growing diamonds in a laboratory:

  • HPHT - High Pressure, High Temperature. A starter ‘seed’ is put under high pressures and temperatures in a similar way to what would have happened in the earth.  Because this happens so much more quickly than in nature, if you look closely enough under a microscope you can see that crystal structure and growth patterns within a synthetic stone are very different to those in a natural one. Colourless HPHT synthetics have been difficult to create as it requires longer growing times and more stable, nitrogen-free growing conditions.
  • CVD – Chemical Vapour Deposition.  This process effectively microwaves a gas that contains carbon (like methane) and the resulting carbon atoms are attracted downwards to create flat plates of diamond. As with HPHT, the process takes place over a number of weeks. Colourless crystals can be grown, but they either take longer to grow, or the CVD has to be combined with HPHT to remove the colour.

We can easily pick out diamond stimulants from real diamonds, either just through experience of looking at these stones or checking them more closely under magnification and / or with a thermal tester, but even experts can’t tell the difference between diamonds that occur naturally and those grown in a lab without some quite sophisticated testing equipment. For this reason, there is concern that synthetic diamonds are getting mixed in with naturally occurring stones by unscrupulous dealers. Harriet and Steffi were really excited to see some of the new technology being developed to combat this during a recent trip to Antwerp. Steffi says:

“The M-Screen+ is a highly advanced screening machine that detects synthetic diamonds that are now becoming more commonly mixed into parcels of natural diamonds. Melee (tiny, facetted diamonds) is poured in to the top of the machine and scanned incredibly quickly - a minimum of 3-4 diamonds are scanned every second which means up to 15,000 per hour at top speed!  It can identify round brilliant melee from 0.005ct up to 0.20ct in a D-J colour range.

Harriet is looking to invest in a similar machine from the GIA. We are confident that the melee we use has already been scanned but we want to be able to demonstrate that we are conscious of this challenge to the diamond industry.  It will mean that we can check diamonds that have been brought to us by a customer from an old piece of jewellery and will ultimately give our customers peace of mind knowing that we are putting these practices in to place.”

So, is it better to use natural or synthetic stones in your bespoke commission?

As we have mentioned, we are more than happy to work with both synthetic and natural diamonds depending on the customer’s preference, and ensure that we are always open and honest about exactly what we are using.  We have in-depth conversations with our customers about what is right for them, including discussions around mining practices as well as the depreciation in price of synthetic stones. Whilst we might prefer to use natural diamonds because we feel this is the best ethical option we are aware that not everyone shares this view and are open minded enough to recognise this. We relish developments in technology that are leading to better traceability in the diamond industry and in the creation of synthetic diamonds too – please feel free to ask us about it!