The 2018 revision to the United States Federal Trade Commission's Guides for the Jewelry, Precious Metals, and Pewter Industries — commonly referred to as the FTC Jewellery Guides — represents the most consequential update to American jewellery advertising standards in a generation. Published in the Federal Register on 24 July 2018, the revised Guides addressed the commercial rise of laboratory-grown diamonds, recalibrated disclosure requirements for treated gemstones, and refined standards for gold alloys and vermeil. Although the Guides carry no force of criminal law in themselves, they define the boundary between legitimate trade practice and deceptive advertising under Section 5 of the FTC Act, making compliance effectively mandatory for any business selling jewellery to United States consumers.

Background and Impetus for Revision

The FTC Jewellery Guides were first issued in 1957 and have been revised periodically to reflect changes in manufacturing, gemology, and consumer expectations. The 1996 revision introduced guidance on treated stones and expanded precious-metal standards. By the early 2010s, however, the rapid commercial scaling of chemical vapour deposition (CVD) and high-pressure, high-temperature (HPHT) diamond production had created a significant definitional problem: the existing Guides defined a diamond as a "natural" mineral, implicitly excluding laboratory-grown material from the term. As laboratory-grown diamonds became indistinguishable from mined stones by conventional gemological testing and began entering the mainstream retail market in volume, industry bodies, laboratories, and consumer advocates submitted extensive comments urging the FTC to revisit the definition.

The FTC opened a formal review process in 2012, solicited public comment in 2016, and published the final revised Guides in 2018 following analysis of submissions from the Gemological Institute of America, the Jewelers Vigilance Committee, the Diamond Producers Association, the International Grown Diamond Association, and numerous individual retailers and manufacturers.

The Redefinition of Diamond

The single most debated change in the 2018 revision was the removal of the word natural from the definition of diamond. The prior Guides defined a diamond as "a natural mineral consisting essentially of pure carbon crystallised in the isometric system." The revised definition reads simply: "a mineral consisting essentially of pure carbon crystallised in the isometric system." The practical consequence is that a laboratory-grown diamond — which shares the same crystal structure, chemical composition, hardness (10 on the Mohs scale), refractive index, and optical dispersion as a mined diamond — may legitimately be described as a "diamond" in advertising and on product labels, provided its laboratory origin is clearly and conspicuously disclosed.

The Guides specify that qualifying terms such as laboratory-grown, laboratory-created, man-made, or the name of the specific growth process (e.g., CVD diamond or HPHT diamond) must accompany any use of the word "diamond" when referring to synthetic material. The FTC simultaneously confirmed that terms such as synthetic remain permissible but are not required. Critically, the Guides explicitly state that it is deceptive to use the unqualified word "diamond" for laboratory-grown material without adequate disclosure, and equally deceptive to imply that laboratory-grown diamonds are identical in all respects to mined diamonds when material differences — including value differences — exist.

The revision also addressed the term simulant: materials such as cubic zirconia and moissanite that merely resemble diamond but differ in composition and properties must never be described as diamonds, with or without qualification. The definitional boundary between a true laboratory-grown diamond and a simulant was thus made explicit.

Disclosure Requirements for Treated Gemstones

The 2018 revision reinforced and clarified existing disclosure obligations for gemstone treatments. The Guides state that sellers must disclose any treatment that has a significant effect on the stone's value or that requires special care by the purchaser. The revision updated examples to reflect contemporary trade practices, including:

• Fracture filling and clarity enhancement in diamonds and coloured stones, which must be disclosed because the treatment affects durability and value.
• Heat treatment of coloured gemstones such as sapphire, ruby, and tanzanite, which the Guides acknowledge is so pervasive in certain categories that disclosure may be framed in terms of whether a stone is untreated rather than whether it has been treated — though sellers must not affirmatively misrepresent treatment status.
• Beryllium diffusion, lead-glass filling, and coating, all of which were specifically noted as requiring disclosure given their material impact on value and, in some cases, durability.

The Guides do not prescribe a single disclosure format but require that any disclosure be clear, conspicuous, and made before the point of sale — not buried in fine print or disclosed only on a receipt after a purchase decision has been made.

Precious Metals, Gold Alloys, and Vermeil

The 2018 revision made targeted adjustments to precious-metal standards. On gold alloys, the Guides retained the longstanding requirement that any product described as "gold" must consist of an alloy of at least ten karats fineness (in United States trade practice), and that karat designations must be accurate. The revision clarified how plated and filled products must be described, reinforcing that terms such as gold-plated, gold-filled, and rolled gold plate carry specific technical meanings that cannot be used interchangeably.

For vermeil — a category of particular interest to fine jewellery designers — the revised Guides retained the definition requiring a base of sterling silver (925/1000 silver) coated with gold of at least ten karats fineness to a minimum thickness of 2.5 microns. The revision clarified that vermeil made on a base metal other than sterling silver must not be described simply as "vermeil" without qualification, as this would mislead consumers about the nature of the product. Products with a base of brass, copper, or other non-silver metals coated with gold must be described as gold-plated rather than vermeil.

Industry and Market Impact

The 2018 revision arrived at a moment of considerable commercial tension between the mined-diamond industry and the laboratory-grown sector. The Diamond Producers Association, representing major mining companies, had argued in its comments that the removal of "natural" from the diamond definition would create consumer confusion and effectively diminish the perceived distinction between mined and laboratory-grown stones. The FTC rejected this argument, concluding that the word "natural" added no meaningful information to the definition given that laboratory-grown diamonds are, by any scientific measure, genuine diamonds — and that the required origin disclosure was sufficient to prevent deception.

For laboratory-grown diamond producers and retailers, the revision removed a significant legal ambiguity that had previously made some marketing claims vulnerable to challenge. For mined-diamond interests, it accelerated the industry's pivot toward marketing the provenance, traceability, and emotional narrative of earth-origin stones as differentiating attributes, rather than relying on definitional exclusivity.

Gemological laboratories, including the GIA, updated their grading report nomenclature in response to the revised Guides. The GIA, which had previously issued "Synthetic Diamond Grading Reports" for laboratory-grown stones, announced in 2019 that it would begin issuing "Laboratory-Grown Diamond Reports" using the same colour and clarity grading scales applied to mined diamonds — a direct reflection of the FTC's position that the two categories are chemically and physically equivalent, distinguished only by origin.

Scope and Limitations

It bears emphasis that the FTC Jewellery Guides apply only within the jurisdiction of the United States. International markets are governed by separate frameworks: the CIBJO (the World Jewellery Confederation) Blue Books, the ISO standards for precious metals, and national consumer-protection regimes in the European Union, United Kingdom, and elsewhere. Many of these bodies have moved toward similar disclosure positions on laboratory-grown diamonds, but the precise terminology, thresholds, and enforcement mechanisms differ. Jewellers operating across multiple jurisdictions must therefore navigate a patchwork of overlapping standards rather than treating the FTC Guides as a universal benchmark.

Within the United States, the Guides are enforced through the FTC's general authority to prosecute unfair or deceptive acts in commerce. Violations do not result in automatic criminal penalties but can lead to consent orders, civil penalties for subsequent violations, and reputational damage. The practical effect is that major retailers, auction houses, and online marketplaces operating in the United States market treat the Guides as binding compliance standards.

Further Reading

• FTC Revised Jewelry Guides, Federal Register Notice, July 2018 — ftc.gov
• GIA Laboratory-Grown Diamond Grading Reports — gia.edu
• American Gem Trade Association (AGTA) Treatment Disclosure Policy — agta.org