The 2018 Federal Trade Commission revision of the Jewelry Guides redefined diamond. The pre-2018 guides had defined diamond as a natural mineral; the revised guides removed the word natural, acknowledging that laboratory-grown diamonds are chemically, physically, and optically identical to mined diamonds and therefore qualify as diamond under the trade-standard definition. The change required the trade to disclose the origin of any diamond — natural or laboratory-grown — at the point of sale, and constrained the use of certain qualifying terms.

What the revision said

The revised definition of diamond reads, in substance: a diamond is a mineral consisting essentially of pure carbon crystallised in the isometric system. The definition does not specify origin; both natural and laboratory-grown material qualify. The revision was accompanied by guidance on the qualifying terms that may be used to indicate origin. Acceptable qualifiers for laboratory-grown diamonds include laboratory-grown, laboratory-created, and [manufacturer-name]-created. The terms cultured diamond and cultivated diamond are permitted only when accompanied by a clear non-mined disclosure.

The revision also addressed the term synthetic. The pre-2018 guides had treated synthetic as the standard term for laboratory-grown gem material, paralleling the usage in coloured stones. The 2018 revision removed synthetic as a recommended term for laboratory-grown diamonds on the grounds that consumer testing showed the term misled significant fractions of consumers into believing the material was an imitation rather than chemically identical to mined diamond. The term may still be used, but only when paired with clarifying language; in practice, the major trade organisations and most retailers shifted to laboratory-grown as the standard.

Industry response

The revision sparked extended debate within the trade. The natural diamond sector — including De Beers, the Diamond Producers Association (which subsequently rebranded as the Natural Diamond Council), and major mining companies — argued that the loss of the word natural from the definition risked consumer confusion and disadvantaged the natural product. The laboratory-grown sector — including Diamond Foundry, ALTR, Lightbox, and a growing number of smaller producers — welcomed the revision as a recognition that their product was diamond in the gemmological sense and that origin disclosure was the appropriate framework rather than terminological exclusion.

De Beers' subsequent launch of Lightbox in 2018 — its laboratory-grown line, priced at a fixed dollar-per-carat far below natural-diamond pricing — was widely read as a strategic response that conceded the gemmological identity of laboratory-grown diamonds while seeking to differentiate the natural product on rarity and value-retention grounds. The natural-diamond sector's subsequent Real is Rare and related campaigns followed similar logic, framing rarity and provenance rather than gemmological distinctiveness as the natural-diamond proposition.

Disclosure in practice

The disclosure regime established by the 2018 revision requires that the origin of any diamond be disclosed clearly and prominently at the point of sale. The disclosure must be in close proximity to the descriptive language and must use the FTC-permitted terminology. Online sellers must include the disclosure on the product page and in any advertising; brick-and-mortar retailers must include the disclosure on the price tag, on any displayed certificate, and in any sales communication. GIA, IGI, and AGS issue separate report formats for laboratory-grown diamonds, with grading parameters substantively similar to natural-diamond reports but distinct in title, document number sequence, and visual styling.

In American trade practice, compliance is monitored by the FTC and by trade organisations including the Jewelers Vigilance Committee. Enforcement actions in the years since the revision have focused on cases of failure to disclose, ambiguous language, and commingling of laboratory-grown with natural inventory at retail. The international position is broadly aligned: the Confederation Internationale de la Bijouterie (CIBJO), the International Diamond Council, and the major foreign trade bodies have adopted comparable disclosure frameworks, with regional variations on permitted terminology.

Effects on the market

The 2018 revision coincided with — and arguably accelerated — the rapid growth of the laboratory-grown diamond market. Wholesale and retail prices of laboratory-grown diamonds fell substantially over the subsequent years, driven by manufacturing scale and competitive pressure; natural diamond prices in some categories came under corresponding pressure as consumers traded down. The two products are now generally treated as distinct categories at retail, with the disclosure regime functioning to permit informed consumer choice between them. The trade vocabulary has converged on natural diamond and laboratory-grown diamond as the standard descriptive pairing.

In the trade

For working dealers and retailers, the practical effect of the revision is the requirement to maintain disclosure on every diamond passing through inventory, to handle laboratory-grown and natural stones with care to avoid commingling, and to use FTC-compliant terminology in all communications. The revision did not change the underlying gemmology of either category; it changed the language and the disclosure framework around them. Six years after the revision, the trade has largely absorbed the change, and the principal remaining tensions concern marketing positioning and pricing rather than terminology.

Further reading

• GIA — Diamond reference
• GIA Gems & Gemology — laboratory-grown diamond articles
• GIA — Laboratory-grown diamond reference
• AGTA — disclosure framework