The FTC Guides for the Jewellery, Precious Metals, and Pewter Industries — formally codified as 16 CFR Part 23 and commonly called the Jewelry Guides — are the principal regulatory instrument by which the United States Federal Trade Commission (FTC) governs truthful representation in the sale of jewellery, gemstones, and precious metals. First issued in 1957 and most recently revised in 2018 following an extensive public-comment period, the Guides carry the force of trade-regulation rules: retailers and suppliers who violate them risk FTC enforcement action, including civil penalties and injunctive relief. For any business selling gemstones or jewellery to US consumers — whether from a bricks-and-mortar store, an e-commerce platform, or an auction house — compliance is not optional.

Legal Status and Scope

The Guides are issued under the FTC Act's prohibition on unfair or deceptive acts and practices in commerce. They do not constitute a separate statute but rather represent the Commission's interpretation of what constitutes deceptive conduct in the jewellery sector. Practically, they bind all sellers in the US distribution chain, from importers and wholesalers to individual retail jewellers and online marketplaces. The 2018 revision modernised several provisions to reflect laboratory-grown diamonds and updated gemological understanding, making it the most substantive overhaul in decades.

The Core Disclosure Principle

The fundamental obligation imposed by the Guides is straightforward: a seller must disclose any treatment or enhancement applied to a gemstone when that treatment is not permanent, requires special care on the part of the consumer, or materially affects the stone's value. These three criteria operate independently — satisfying only one is sufficient to trigger the disclosure obligation. The Guides further require that disclosure be made clearly and conspicuously at the point of sale, meaning that burying a treatment disclosure in fine print or providing it only upon direct inquiry is unlikely to satisfy the standard.

Heat Treatment: The Standard-Practice Exception

Heat treatment occupies a distinctive position within the Guides because it is so pervasive in the trade for certain species — most notably corundum (ruby and sapphire) and tanzanite — that the FTC has historically treated it as an industry norm rather than a material alteration requiring routine disclosure. The Guides do not require a seller to affirmatively state that a ruby has been heated when heating is the standard commercial practice for that variety. However, the converse carries significant weight: if a stone is unheated and that absence of treatment commands a measurable premium in the market — as it demonstrably does for fine Burmese rubies and Kashmir sapphires — then representing the stone without clarifying its unheated status, or implying an unheated status that does not exist, would be deceptive. In practice, the trade has adopted the convention of disclosing unheated status as a positive attribute, precisely because the Guides create liability for misleading omissions.

Treatments Requiring Mandatory Disclosure

Several enhancement categories are explicitly addressed in the Guides as requiring disclosure in virtually all circumstances:

• Fracture filling and clarity enhancement: Filling surface-reaching fractures with glass, resin, or oil — as practised routinely with emeralds (cedar oil, synthetic resins) and occasionally with rubies (lead-glass filling) — must be disclosed. The treatment is neither permanent nor invisible to the consumer's care requirements, since heat, ultrasonic cleaning, and certain chemicals can damage or remove the filler.
• Diffusion treatment: Surface diffusion of beryllium into corundum to alter colour, or titanium diffusion to create asterism, produces a colour or optical effect that is confined to a shallow surface layer and is therefore not intrinsic to the stone. The Guides require disclosure, and the FTC has indicated that terms such as "diffusion-treated sapphire" or "beryllium-treated sapphire" are appropriate descriptors.
• Dyeing: The introduction of artificial colourants into porous or fractured stones — common in jade, turquoise, coral, and some lower-grade rubies — must be disclosed. A dyed stone may fade, bleed colour in contact with solvents, or otherwise change in appearance, directly implicating the consumer's care obligations.
• Irradiation: Colour alteration by gamma-ray, electron-beam, or neutron bombardment, used commercially in blue topaz, certain fancy-colour diamonds, and some tourmalines, requires disclosure. Where irradiation is combined with subsequent heating (as in most blue topaz), the combined treatment is still subject to disclosure requirements.
• Coating: The application of surface coatings — lacquer, metallic vapour deposition, or polymer films — to alter apparent colour or lustre must be disclosed, as such treatments are neither durable nor permanent under normal wear conditions.

Nomenclature and Species Names

The Guides address not only treatments but also the proper use of gemstone species and variety names. A seller may use the term "ruby" for a treated ruby, provided the treatment is disclosed as required. What the Guides prohibit is the use of a species name in a manner that implies a quality, origin, or natural status the stone does not possess. The 2018 revision clarified that the term "natural" may be used to distinguish mined stones from laboratory-grown counterparts, but that it does not by itself imply the absence of treatment — a nuance of considerable practical importance given the prevalence of treated natural stones in the market.

The Guides also regulate the use of geographic qualifiers. Describing a stone as "Ceylon sapphire" or "Burmese ruby" implies a specific geographic origin; if the seller cannot substantiate that origin — ideally through a laboratory origin report from a recognised gemmological laboratory — use of such a qualifier risks being deemed deceptive.

Laboratory Reports and the Guides

While the FTC Guides do not mandate the use of independent gemmological laboratory reports, such reports from recognised laboratories — including the Gemmological Institute of America (GIA), Gübelin Gem Lab, Swiss Gemmological Institute (SSEF), and Lotus Gemology — have become the practical mechanism by which sellers substantiate disclosure claims and defend against FTC liability. A report documenting treatment status, origin determination, and species identification provides an evidentiary record that a seller exercised reasonable diligence. The AGTA (American Gem Trade Association) maintains its own treatment disclosure code that aligns closely with the FTC Guides and is widely adopted by its members as a best-practice standard.

Relationship to AGTA Disclosure Standards

The American Gem Trade Association's treatment disclosure code, which predates several iterations of the FTC Guides and has been developed in close consultation with the trade, provides a more granular treatment taxonomy than the Guides themselves. AGTA classifies treatments on a lettered scale (A through F and beyond) corresponding to specific enhancement types, and its member code requires disclosure at every level of the supply chain. The FTC has, in various guidance documents, acknowledged industry self-regulatory codes as relevant evidence of reasonable trade practice, meaning that AGTA-compliant disclosure is generally regarded as consistent with FTC requirements — though FTC compliance ultimately turns on the statutory standard rather than any private code.

Practical Implications for the Trade

For jewellers and gemstone dealers, the Guides create a disclosure architecture that operates at every transaction: from the cutter or treater who first processes the stone, through the wholesaler, to the retail point of sale. A seller who receives a stone without adequate treatment disclosure from a supplier is not automatically absolved of FTC liability if the stone is subsequently sold without disclosure to a consumer. This chain-of-custody obligation has driven the adoption of treatment documentation practices across the supply chain, and has reinforced the commercial value of gemmological laboratory reports as disclosure instruments.

The 2018 revision's treatment of laboratory-grown diamonds — removing the word "synthetic" as a required qualifier and permitting terms such as "laboratory-grown," "laboratory-created," or "man-made" — illustrates the Guides' ongoing evolution in response to market developments. Similar scrutiny may be applied in future revisions to laboratory-grown coloured stones, which are increasingly present in the commercial market.

Further Reading

• FTC Jewelry Guides — 16 CFR Part 23 (ftc.gov)
• AGTA Gemstone Treatment Codes (agta.org)
• GIA Commentary on the 2018 FTC Jewelry Guides Update (gia.edu)