NDC Prevails in U.K. Case Over Lab-Grown Diamond Advertising
NDC filed a complaint against Skydiamond for use of phrases like “diamonds made entirely from the sky.”

London—The U.K.’s Advertising Standards Authority (ASA) announced it has upheld the Natural Diamond Council’s complaint against retailer Skydiamond for misleading marketing and advertisement of lab-grown diamonds.
The online fine jewelry retailer uses a patented process to create diamonds from atmospheric carbon dioxide and rainwater using renewable energy from solar and wind power, its website states.
The NDC’s complaint alleged that it was misleading for Skydiamond to use the terms “Skydiamonds,” “diamonds,” and “diamonds made entirely from the sky” in ads it featured in early 2023 in press, on its Instagram, and on its website.
It also called into question the use of the words “real diamond” in a section of the retailer’s FAQ page that answered the question “Are Skydiamonds real diamonds?” with “Each Skydiamond is a perfectly formed real diamond.”
In its ruling, the ASA, which is the U.K. equivalent of the Federal Trade Commission (FTC), sided with NDC, stating that the ads did not make it clear that the diamonds were lab grown.
It also said the above terms were misleading, and the ads breached the U.K. Code of Non-Broadcast Advertising, Sales Promotion and Direct Marketing rules 3.1 and 3.3, with regards to misleading advertising, and 3.9, with regards to qualification.
The code states, “marketing communications must not mislead the consumer by omitting material information. They must not mislead by hiding material information or presenting it in an unclear, unintelligible, ambiguous, or untimely manner.”
All of Skydiamond’s ads included clear gemstones and references to diamonds, the ruling said, and it considered consumers would understand “diamond” in insolation to mean a naturally occurring mineral of crystallized carbon.
While some consumers would be aware that diamonds could be manufactured in a lab, ASA said, many would not.
ASA directed Skydiamond not to use the above terms to describe their lab-grown diamonds without a clear and prominent qualifier, such as “synthetic,” “laboratory-grown” or “laboratory-created,” or another way of conveying the same meaning to consumers in a direct and obvious manner.
It also told the retailer the ads must not appear again in the form complained about, and to not use the claim “real diamonds” to describe lab-grown diamonds.
Skydiamond said it plans to appeal the ruling, calling it “a mistake.”
“Our website and all of our marketing, indeed our very name, make clear that our diamonds come from the sky, we make them or mine them from the sky," said Dale Vince, founder of Skydiamond.
"We make that very clear. Nobody could possibly think they are conventional stones ripped from the bowels of the earth at enormous environmental cost, and nobody actually has. This complaint is not based on actual confusion on the part of customer; it comes from the trade body for diamond mining companies, [and] it is an attempt to use the ASA for anti-competitive purposes and it utterly baseless."
The NDC, which filed in March 2023, based its complaint on the Diamond Terminology Guideline, a reference document that, as of 2020, is assured and recognized by Trading Standards in the U.K. market.
The U.K.’s National Association of Jewellers, along with leading industry organizations, have endorsed the guideline, which is built on the ISO 18323 Standard (“Jewellery – Consumer confidence in the diamond industry”) and the CIBJO Diamond Blue Book.
The FTC has its own rules on diamond terminology, but it is not recognized for diamonds sold outside the United States.
The Diamond Terminology Guideline states that all documents, websites, and other means of communication intended to sell, buy, and promote natural diamonds, lab-grown diamonds, gemstones, lab reports, and natural and lab-grown diamond jewelry must use “synthetic,” “laboratory-grown” or “laboratory-created” when referring to lab-grown diamonds, a directive the ASA references in its ruling.
In one section of its lengthy response to NDC’s complaint, Skydiamond called the guideline a tool that “should not be, and did not profess to be, the only basis for defining the origin of a diamond or for determining definitively whether diamond ads were misleading to an average consumer.”
Skydiamond also argued that of the 23 steps in its “novel and innovative” production process, only the CVD step was shared with conventional lab-grown diamond production processes, and commercialization of its process post-dated the introduction of the Diamond Terminology Guideline, so it was not considered for inclusion.
The ASA acknowledged in its ruling that the guideline had been updated in 2023, but there were no major changes to the 2020 version.
And, although it agrees Skydiamond’s production process differs from other diamond growers, ASA said the diamonds were lab grown nonetheless and consumers needed to know that before making a transactional decision.
The NDC’s complaint to the ASA regarding misleading terminology in advertisements for lab-grown diamonds initially included three other U.K. retailers—Stephen Webster, Lark & Berry, and Idyl.
According to NDC, ASA dropped its case against Stephen Webster but did note that its ruling in the Skydiamond case also applies to Stephen Webster’s marketing and communications.
A spokesperson for Stephen Webster said the company had no comment on the ruling.
The ASA investigated ads from the other two retailers and considered them to be in breach of code—Lark & Berry for the use of “cultured diamond” and “diamond” without a qualifier when referring to synthetic diamonds, and Idyl for the use of the terms “diamonds,” “diamond sparkle,” “fine diamond jewelry,” “sustainable diamonds,” and “Diamonds of the Future” in the same context.
Lark & Berry agreed to amend the ads with qualifiers such as “synthetic,” “laboratory-grown,” and “laboratory-created.”
Idyl also agreed to amend their advertisements that targeted U.K. consumers.
Both rulings have been published as informally resolved on ASA’s website.
The Latest

A set of four Patek Philippe “Star Caliber 2000” pocket watches is part of Sotheby’s upcoming auction in Abu Dhabi.

The Brazilian jeweler’s latest book marks her namesake brand’s 25th anniversary and tells the tale of her worldwide collaborations.

The Submariner Ref. 1680 with a Tiffany & Co. dial came from the original owner, who won it as a prize on the game show in the 1970s.

With their unmatched services and low fees, reDollar.com is challenging some big names in the online consignment world.

The new integration allows users to manage shipments directly from the Shopify dashboard.


At Converge 2025, Editor-in-Chief Michelle Graff attended sessions on DEI, tariffs, security, and more. Here are her top takeaways.

Six people were shot last week at an Oakland cash-for-gold shop as employees exchanged gunfire with individuals trying to rob the store.

Jewelers of America is leading the charge to protect the industry amidst rising economic threats.

The jeweler has expanded its high jewelry offering, which launched last year, with new pieces featuring its cube motif that debuted in 1999.

Ben Bridge Jeweler and Lux Bond & Green were a part of the pilot program.

Associate Editor Natalie Francisco shares eight of her favorite jewelry looks from the 77th annual Primetime Emmy Awards, held Sunday night.

It’s predicting a rise in retail sales this holiday season despite economic uncertainty and elevated inflation.

It included the sale of the 11,685-carat “Imboo” emerald that was recently discovered at Kagem.

The newly elected directors will officially take office in February 2026 and will be introduced at the organization’s membership meeting.

Associate Editor Lauren McLemore headed out West for a visit to Potentate Mining’s operation hosted by gemstone wholesaler Parlé Gems.

Fordite is a man-made material created from the layers of dried enamel paint that dripped onto the floors of automotive factories.

Gilbertson has worked as a researcher, jeweler, lapidary artist, appraiser, and business owner throughout his decades in the industry.

Located in the revamped jewelry hall at the retailer’s New York City flagship, this opening is Tabayer’s first shop-in-shop.

The new, free app offers accessible educational content, like games and podcasts, for U.S. retailers.

As the gold price rises, the manufacturer is offering a 100 percent payout through Sept. 30 for gold clean scrap.

Jacob & Co. partnered with the German technology company on two pairs of headphones, one set with diamonds and the other with sapphires.

Guillermo del Toro’s 2025 “Frankenstein” will feature 27 jewels and objects from the storied brand, including pieces from its archives.

The Waldorf Astoria New York’s grand reopening this past summer means a homecoming for the industry group’s annual event.

Anglo plans to merge with Teck Resources Ltd. to form Anglo Teck. The deal changes nothing about its plans to offload De Beers.

The 9.51-carat fancy vivid blue diamond, which set two world auction records at Sotheby’s in 2014, is estimated to fetch up to $30 million.

The industry veteran joins the auction house as it looks to solidify its footprint in the jewelry market.

The nonprofit awarded four students pursuing a professional career in jewelry making and design with $2,250 each.