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Mines were the only source of the gemstone until 1955, when General Electric (GE) announced it had successfully replicated the extreme conditions that produce diamonds deep within the earth inside its laboratory.
Initially, lab-grown diamonds were used mainly for industrial applications.
Today, lab-made diamonds are virtually identical in quality and composition to natural-mined diamonds, but without the human toll or negative environmental impact of mining operations.
Russia has the biggest natural diamond industry in the world, but Botswana has the distinction of producing the highest-value diamonds, as well as being the second-largest producer of diamonds by volume.
Global rough diamond production in 2017 was estimated at 150 million carats.
The production of synthetic diamonds was estimated at around 15 million carats, with 99% targeted for industrial use. China dominates this segment, accounting for about 90% of global production.
The lab-grown diamond segment of the jewellery market was worth US$1.9bil, or a tiny fraction of the US$87bil diamond jewellery market size, according to analyst Paul Zimnisky.
Growth in the lab-grown diamond segment, however, is projected to be at a robust rate of 22% annually, hitting US$5.2bil by 2023 and US$14.9bil by 2035.
To capture this demand, De Beers is building a new diamond factory in Oregon that has the capacity to produce 500,000 carats a year, while Diamond Foundry, which opened a new factory in Washington last year, aims to produce one million carats by the end of 2019.
Global output of polished synthetics is growing by 15% to 20% per year as manufacturing costs fall, Bain & Company said in a report last month.
i: The High Pressure, High Temperature (HPHT) process, which was used by GE in the 1950s, replicates the way natural diamonds were formed about 100 miles beneath the earth’s surface millions of years ago. It uses pressure of more than 1.5 million pounds per square inch and temperatures above 2,000 degrees Celsius in a machine to transform carbon into diamonds.
Scientists at Element Six, part of De Beers, liken the pressure required to standing the Eiffel Tower upside down on a drinks can.
ii: The Chemical Vapour Deposition (CVD) process, which became viable in the 1980s, does not require high pressure.
A hydrocarbon gas mixture is ionised by microwaves or lasers in a vessel at temperatures of about 800 degrees Celsius. This breaks the molecular bonds of the gases, spurring carbon atoms to be deposited on a diamond seed, growing into a crystal, layer by layer over days and weeks.
Many of the new lab-grown diamond companies use CVD, which gives the diamond creator greater control over the process.
The production cost to make high-tech diamonds in a laboratory has plummeted to as little as US$300 a carat from about US$4,000 over the past decade, according to consultants Bain & Company.
Meanwhile, producers of synthetic industrial-quality diamonds have been advancing their capability through improved technology, which has enabled them to increase the quality of their product from industrial to near-gem quality.
Given that billions of carats of industrial-quality diamonds are produced each year, it becomes apparent that lab-created near-gem production could be in the hundreds of millions of carats.
De Beers’ lab-grown jewellery company Lightbox is selling one carat diamonds for US$800, about a fifth of the price of rival man-made stones and one-tenth of the cost of buying a similar natural gem. Lightbox, however, neither sells loose diamonds nor engagement rings, only fashion jewellery such as necklaces.
But even before LightBox, the price of man-made diamonds was already on the decline. According to reports, retail prices of man-made diamonds have nearly halved in the past two years, while wholesale prices have dropped by two-thirds. Generic 1-carat lab-grown diamonds were selling at an average discount of 42% relative to natural stones in late November 2018 compared to 29% in January, Zimnisky said.