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 lab grown diamonds. 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 diamoennd 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.)
What are lab grown diamonds?
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. 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.
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.
However, some lab diamond companies, including the Leonardo DiCaprio backed Diamond Foundry in the US, are certified as carbon neutral and use only renewable energy. But others 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.
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. 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.
– Read the rest of the interesting report here