Lab-grown diamonds come under the spotlight

Within months of launching her Lark & Berry jewellery brand, Laura Chavez received a letter in 2018 co-signed by the London Diamond Bourse and the National Association of Jewellers. It informed her that, in their opinion, the wording on her website was incorrect and misleading consumers. Chavez was dealing exclusively in laboratory-grown diamonds and chose to use more creative descriptions, such as cultured diamonds.

After speaking with her lawyer, Chavez chose not to yield. Instead, she responded with a letter of her own, published on her website. The tone was bullish — starting with a Winston Churchill quote that speaks to the virtue of having enemies (“That means you’ve stood up for something . . . ”) — and claiming that “any new, innovative field faces pushback”. It suggested the reason for the “intimidation” was because “the mined diamond industry is scared”.

In 2023, another communication arrived: this time, from the Advertising Standards Authority (ASA). “When I saw it, I was like, ‘OK . . . another one of these people telling us we need to change our terminology’,” says Chavez. “But I guess this was a serious one.”

Lark & Berry was the subject of an ASA investigation, following a single complaint. It told the jewellery brand that it needed to change its wording to clearly mark its products as laboratory-grown diamonds, or laboratory-created diamonds, or synthetic diamonds. These are the approved terms in the 2020 Diamond Terminology Guideline created by the National Association of Jewellers, which is linked to two international standards: the ISO 18323 Standard and the CIBJO Diamond Blue Book.

This time, Chavez agreed, and has implemented the changes. As she says, shoppers tend to search for “laboratory-grown diamonds” rather than “cultured diamonds”, so she sees it as beneficial for the brand’s online search engine optimisation. The case was marked as informally resolved in February.

The single complaint made to the ASA was from the Natural Diamond Council, a marketing body funded by the diamond industry to promote mined diamonds. It was not the only one it made. Executives employed by the NDC trawled through the websites, ad campaigns and social media profiles of brands it deemed to be disregarding what it considered to be the correct terminology to build cases against them.

Belgian laboratory-grown jewellery brand Idyl was one of those that fell in the NDC’s crosshairs. Its complaint to the ASA — that Idyl was using the word “diamond” without a qualifier to make it clear the stones were man-made — was investigated. This, too, was marked as informally resolved by the ASA in January.

“We are pleased that the Advertising Standards Authority has reinforced the need to ensure that consumers clearly understand when they are buying a laboratory-grown and not a natural diamond,” says David Kellie, NDC’s chief executive. “Unfortunately, as seen in the complaints filed, there are some retailers who use language that is intended to confuse consumers and, given the significant and growing price difference between laboratory grown and natural diamonds, this will leave the consumers feeling misled by their purchase. It is important that all retailers clearly disclose the nature of the product that they are selling.”

The NDC’s big ASA win came in April when the authority released a full ruling on The Sky Mining Company, which trades under the brand name Skydiamond. The Cotswolds-based laboratory-grown diamond producer is the brainchild of Dale Vince OBE, founder of green energy company Ecotricity. It has a distinct marketing pitch: it removes carbon from the air to use as the carbon starter for its synthetic diamonds.

The NDC challenged some of its rhetoric around this concept as misleading, such as an ad that stated its products were “diamonds made entirely from the sky”. It also claimed that consumers would be confused as to whether Skydiamonds were natural or not. The ASA agreed, delivering a lengthy ruling upholding the complaint, despite a robust defence by Skydiamond.

In the interim, Skydiamond is reviewing its communication, and plans to use the term “man-made diamonds” for now — one that was not officially listed by the ASA as an acceptable alternative — but Vince says he is appealing against the decision “and if needs be, we’ll seek a judicial review in order to reverse it”.

“We are disappointed with the way the ASA even began this,” he says. “It was clearly a competitor complaint and there is a different process for that.”

Vince says he plans to complain to the ASA against NDC’s own use of the word “natural”, “because we think that there is nothing natural about the process by which diamonds are mined from the ground.”

The NDC has also been working with City of Hull Trading Standards to target retailers selling laboratory-grown diamonds in the city. This particular Trading Standards team already had experience in the jewellery industry, having run investigations into the sale of precious metals over the past decade.

Now, it is also focusing its attention on laboratory-grown diamonds, inspired by a meeting with NDC head of UK Lisa Levinson at the Chartered Trading Standards Institute Conference in Bristol in 2022.

The focus of the investigation is two-fold: officers are looking at marketing materials to ensure the Diamond Terminology Guideline is being upheld, but are also going into the field with qualified gemmologist Charlotte Rose to test stones to ensure what is being sold as a natural stone is just that. “In terms of the terminology, it was quite interesting as there were quite a few retailers using abbreviations, like lab grown,” says Hull City Trading Standards manager Chris Wilson. “We’ve also come across a laboratory-grown diamond clearly purported as a natural diamond ring [with a price tag of more than £3,500].”

Hull stands alone in its battle for transparency around laboratory-grown diamond sales. Should other authorities choose to follow suit, they might look to its blueprint, but there is no guarantee, says Wilson, as there is little cohesion between Trading Standards agencies across the UK.

Despite this, the Hull activity mixed with the NDC’s ASA complaints show that the NDC — which for many years pushed its nomenclature agenda aggressively, but with little bite to back the bark — now has some teeth, and Kellie believes consumers will be all the safer for it, as “visible enforcement by British authorities will serve as . . . a deterrent to the very small minority of players” whose advertising lacks requisite clarity.