On a grey January morning in 2019 Meghan Markle emerged onto a London street on her way to a meeting. She wore a smart coat and heels, but it was not her clothing that caught the attention of the world. It was a pair of glittering drop earrings embedded with diamonds that had been grown in a lab.
It took just five days to grow the diamonds adorning Markle’s ears according to Sidney Neuhaus, co-founder of Kimaï, the company that made them. Based in Antwerp, the capital of the world’s diamond business, both she and her co-founder Jessica Warch grew up in diamond families. Nauhaus’s father owns a diamond jewellery shop, and her grandfather worked for De Beers, making his career in diamonds after World War Two.
Despite their illustrious family histories in the trade, Neuhaus and Warch chose to break away from conventional diamonds because of the environmental and humanitarian toll of extracting them. Millennials and now Generation Z – who together are the main purchasers of diamonds for engagement rings – are moving away from conventional diamonds, with nearly 70% of millennials considering buying a lab grown alternative. (Read more about the rise of guilt free gems.)
So what are lab grown diamonds, and are they really a more sustainable alternative to traditional mined diamonds?
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First up, a lab-grown diamond is a diamond: chemically, physically and optically identical to a mined diamond. Naturally occurring diamonds are forged in the crushing pressure and immense heat of the Earth’s mantle around 100 miles underground. Most were formed between 1bn and 3bn years ago at a time when our planet was hotter than it is today.
There is little to differentiate lab grown diamonds from those that occur naturally other than the way they are made (Credit: Getty Images)
Lab-grown diamonds are also created using extreme pressure and heat, but inside a machine rather than the bowels of the Earth.
There are two ways to grow a diamond. Both involve starting with the “seed” (a flat slither) of another diamond. The first lab diamond was made using a High Pressure High Temperature (HPHT) system, where the seed is then placed amidst some pure graphite carbon and exposed to temperatures of about 1,500C and pressurised to approximately 1.5 million pounds per square inch in a chamber.
More recently, another way to grow a diamond was discovered, called Chemical Vapor Deposition (CVD). This involves putting the seed in a sealed chamber filled with carbon-rich gas and heating to around 800C. Under these conditions the gases begin to “stick” to the seed, growing a diamond carbon atom by atom.
Lab-grown diamonds are created using extreme pressure and heat inside a machine rather than the bowels of the Earth
The technology behind lab diamonds has made crucial advances in recent years, allowing companies to grow higher quality diamonds more rapidly and more cheaply. It has meant growing competition between lab diamond and mined diamond companies. Today, it costs $300 to $500 per carat to produce a CVD lab-grown diamond, compared with $4,000 per carat in 2008, according to a report commissioned by the Antwerp World Diamond Centre (AWDC).
Lab-grown diamonds are a rapidly growing trend in the industry. Young diamond-buyers are drawn to them by price, transparency and for environmental reasons, with this segment of the market increasing by between 15% and 20% annually, according to the AWDC report. The growth is expected to continue as more jewellers start to sell lab diamonds and more labs are launched.
But lab diamonds are not without fault. A distinct lack of transparency makes it difficult to source accurate data to compare the carbon footprints of mined and lab diamonds, but the energy needed to produce a lab diamond is significant. One report on the topic, commissioned by the Diamond Producers Association, suggests that the greenhouse gas emissions produced mining natural diamonds is three times less than those created when growing diamonds in a lab. It’s worth noting that the DPA represents seven of the world’s largest diamond miners, including De Beers, Alrosa and Rio Tinto.
Extremely high temperatures are needed to grow diamonds in the laboratory, which uses a large amount of energy (Credit: Getty Images)
However, some lab diamond companies have been warned by the Federal Trade Commission in the US to be careful when presenting themselves as “eco-friendly” without evidence to substantiate these claims. Companies including Ada Diamonds and the Leonardo DiCaprio backed Diamond Foundry in the US were among them. However, the latter says that it is certified as carbon neutral by the third party Natural Capital Partners and uses only renewable energy.
Figures published by Diamond Foundry suggest that the total environmental footprint of mined diamonds is much higher than lab diamonds. “It takes an entire factor more energy to extract an underground diamond from Earth than it takes to create one above ground... On top of this, the energy used in mining is generally dirty diesel versus renewable energy in our above-the-ground production,” says a blog post on their website.
An estimated 250 tonnes of earth is shifted for every single carat of diamond. For context, 148 million carats were mined in 2018. Indeed, some mines are now so huge they can be seen from space using Nasa’s Terra satellite. A 2014 report by consulting firm Frost & Sullivan also showed that mined diamonds require twice as much energy per carat than those grown in a lab. It estimated that 57kg of carbon are released into the atmosphere for every single carat mined, but claimed lab grown diamonds release barely more than a few grams, but this assumes renewable energy is used and some in the industry have cast doubt on the reliability of the report.
An estimated 250 tonnes of earth is shifted for every single carat of diamond
The figure is far less than that estimated by another consultancy Trucost, which produced the previously mentioned report for the Diamond Producers Association. They put the carbon emissions from lab grown diamonds at 510kg CO2 per polished carat and those from mined diamonds at 160kg CO2 per polished carat.
Researchers at Anglo American, the parent company of De Beers, have also been working on a project to reduce the carbon footprint of mined diamonds by capturing carbon dioxide inside a porous mined rock known as kimberlite. Led by the company’s geologist Evelyn Mervine, they have been developing a process called “mineral carbonation” as a way of off-setting the greenhouse emissions that come from the mining process.
Diamond mining can involve the removal of vast amounts of earth and rock which creates holes so big they can be seen from space (Credit: Alamy)
But the environmental damage from diamond mining goes further than simply its carbon emissions. Diamond mining has been linked to pollution of water sources used by local people due to acid mine drainage. This occurs when minerals from the mined rocks seep into the water supply. The University of Waterloo in Canada describes it as “one of the mining industries top environmental liabilities”. Although acid mine drainage is not exclusively a problem for the diamond industry – it occurs at many metal and coal mines too – researchers at the University of Waterloo have been working with the Diavik diamond gem mine in Canada’s Northwest Territories to reduce this pollution from waste rock.
Mining has also caused the destruction of habitats in Canada and beyond. In 2016, The Wall Street Journal reported that De Beers had killed over 18,000 fish draining a Canadian lake for diamond mining. In India, diamond mines have been blamed for placing highly endangered tiger populations under further pressure.
Diamond mining has been linked to pollution of water sources used by local people due to acid mine drainage
So, while neither lab diamond nor mined diamond industries are perfect, the wider environmental price from the latter can be higher. Indeed, the former Tiffany chief executive Michael J. Kowalski wrote in a 2015 New York Times opinion piece, “few industries in the world have a larger environmental and social footprint than mining”.
Indeed, the environmental and humanitarian harms from diamond mining are closely intertwined. Some diamond mines employ miners on low wages in unsafe conditions. Even diamonds extracted in accordance with the Kimberley Process, established in the early 2000s to reduce the trade in conflict diamonds, can have obscured origins. A source in the conflict resources team at the non-governmental organisation Global Witness, who wishes not to be named to protect their identity, says that there are many holes in the process. “The definition of a ‘conflict diamond’ as the Kimberley Process sees it is a diamond which is funding an armed group which is trying unseat a legitimate government,” she says.
Over the years, the links between mined diamonds and human rights abuses have evolved far beyond that definition. “The Kimberley Process has failed to keep up,” she adds. She gives an example of a huge discovery of diamonds in Zimbabwe in the mid-2000s that led to the deaths of hundreds of civilian miners. The diamonds found here were traded in Antwerp and Dubai, “circulating freely on international markets”, according to a Global Witness report.
Diamond mining provides employment in developing countries but is also surrounded by humanitarian concerns (Credit: Getty Images)
Further down the supply chain, things get murkier still, as once a stone is cut and polished it is no longer traced by the Kimberley Process. Diamonds pass through multiple trading hubs on their journey from mine to shop, and often end up mixed with diamonds from other countries of export. The result is that even among diamonds with Kimberley Process certification, many companies cannot trace the diamonds they use back to their country of origin. A 2018 report from Human Rights Watch, which investigated major jewellers including Buglari, Pandora, Cartier and Tiffany & Co, says, “None of the companies can identify all of their diamonds’ individual mines of origin.”
But there is also concern that the demand for lab diamonds could take away jobs from resource-rich developing countries. Brad Brooks-Rubin, previous special advisor on conflict diamonds to the US Department of State and now managing director at The Sentry/Enough Project, an organisation that aims to end mass atrocities in Africa’s deadliest conflict zones, asks, “is it ethical to guide people away from buying diamonds from developing countries, where a million people or more rely on the work?”
The humanitarian questions around lab and mined diamonds remain knotty, but there is one way that lab diamonds come out on top in terms of environmental impact. Diamonds for jewellery make up only 30% of the market, with the rest sold for use in drilling, cutting and grinding. It’s in this area that lab diamonds can actually be used for environmental benefit.
A thin coating of diamond has also been shown to reduce friction in moving mechanical parts, from windmills to cars
One of their industrial uses is disinfecting polluted water sources. This is done by adding the mineral boron during the diamond-growing process to create a “boron-doped diamond”, which is able to conduct electricity. By then applying current to the diamond it oxidises otherwise toxic organic compounds in a process called mineralisation, which turns them into a biodegradable form.
Jason Payne, chief executive of Ada Diamonds, argues that lab diamonds can also significantly reduce the carbon footprints in communications and transport. The reason lab diamonds have the edge on mined diamonds here is down to their purity and hardness, with lab-grown diamonds found to be ten times more durable than natural diamonds.
Diamonds are among the hardest materials on the planet, which means the only way to polish a rough diamond is with another one (Credit: Getty Images)
“A diamond is the ultimate known semiconductor… far superior to silicon or other materials,” says Payne. Using lab diamonds in transistors reduces the energy lost as heat as electricity is conducted from the power plant to devices such as your mobile phone as it charges. The US Department of Energy reports that diamond-based components reduce these losses by up to 90%.
A thin coating of diamond has also been shown to reduce friction in moving mechanical parts, from windmills to cars. Nissan reported a reduction in friction between engine parts of approximately 40% when using diamond film. In contrast with lab diamonds, mined diamonds “do not have the purity required for many of these applications,” argues Payne.
The diamond illusion
In the past, when faced with existential threat, the mined diamond industry has advertised its way out of trouble. Indeed, the reason many of us are so fond of diamonds stems from a clever advertising campaign launched by De Beers in 1947. The company forever changed culture when it convinced us that “a diamond is forever”, and that a diamond ring is a quintessential part of getting engaged. The idea that diamonds are rare is also a carefully crafted marketing illusion. In fact, excessive supply of diamonds has recently led to speculation that De Beers will reduce its number of contracted buyers. The company has confirmed it will review the contracts of its rough diamond customers when they expire at the end of this year.
But as lab diamonds grow in popularity, the usual rebranding effort doesn’t appear to be working for mined diamonds. The industry faces issues of oversupply and a slump in demand across the globe – particularly in China, the world’s second largest diamond market, where sales declined by 5% in 2019. At an industry meeting on the rooftop of a fancy London hotel at the end of November, Simon Forrester, chief executive of the UK’s National Association of Jewellers told an audience that, “as an industry we are suffering, [due to] lacking consumer confidence”. The diamond behemoth De Beers recently announced it cut production by 15% in late 2019 due to weak prices.
Demand for diamonds is declining in many parts of the world at a time when the industry has an oversupply of the gemstones (Credit: Getty Images)
As environmental sustainability and social welfare rise on consumers’ agenda, Neuhaus says she has noticed a change in atmosphere in Antwerp. “When I was younger [Antwerp was] super dynamic. Business was flourishing for everyone. Now when I go back you can feel there is another mood… there is less money than before,” she says. Neuhaus’s story of splitting away from her traditional family business into the more high-tech world of lab-grown diamonds is symbolic of this change in the air. With clients like Meghan Markle on her books, her lab diamond business is thriving.
When it comes to jewellery, Neuhaus says that the real value in diamonds, mined or lab-grown, is not really about price or rarity. “It’s more about the emotional value,” she says, fingering a long gold necklace with a green pendant on it hanging around her neck. “This was the first piece of jewellery I made for myself.” For this reason, as long as diamonds hold their emotional resonance, jewellers will continue to sell them, both lab-grown and mined.
This article has been amended as it originally stated that lab diamonds were ten times harder than mined diamonds – in fact they are ten times more durable. In addition, on diamond marketing campaigns, it has also been amended to state that the idea of diamonds being rare has been a carefully crafted marketing illusion, rather than “rare and precious”.
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