Also called cultured diamonds, synthetic diamonds are man-made stones with the same composition or molecular structure as their natural counterparts. Both are crystallised carbons. The difference is that synthetics can take as little as a few days (up to several months) to make in a laboratory, whereas natural diamonds can take millions of years to form underground.
There are several ways to make synthetics. One of the first companies to produce them was Florida-based Gemesis, which uses the high pressure high temperature (HPHT) process. Delaware-based Apollo uses the chemical vapour deposition technique. Another US-based company, Gem Life, uses carbons from humans and animals. In this case, the carbon is heated, turned into graphite and put into a diamond-synthesising machine, where more heat and pressure
are applied, before it becomes a gem. The HPHT method produces coloured synthetics, whereas Apollo produces white and coloured stones.
Scott Thompson, founder of Carat and a director of Gemesis in Hong Kong, says the synthetic-diamond market is still in its infancy, but expects demand to grow steadily during the next few years. Based on his four years of experience, Thompson says buyers are usually women from their 20s to 40s.
'If people haven't owned natural diamonds before, they seem more averse to the idea of synthetic diamonds,' he says. 'We have customers who collect [natural diamonds], but use synthetics as fun jewellery to mix things up.'
Thompson says there's a similar trend in fashion. 'It's like teaming a Zara T-shirt with a Chanel jacket - people like to mix their jewellery.'
That said, synthetics aren't cheap. They're still diamonds - just more affordable than natural stones. Thompson says a synthetic yellow diamond is usually a quarter the price of a natural one, or at least US$5,000 per carat. Pink and blue synthetics cost about 5 per cent of naturals, with prices starting about US$8,000 per carat (natural ones can cost US$200,000 and up per carat).