Sources

How we use these

Every page on this site carries its own sources block with the specific citations it relies on. This page collects the standing set - the documents almost every material claim traces back to.

The important rule: we cite the primary regulation, not a secondary retelling of it. Several jewelry brands publish good explainers of the vermeil threshold, and we could have cited those. We read the regulation instead, because a brand summarizing a rule about its own product is a step removed from the rule.

The standing list

• 16 CFR Part 23 - Guides for the Jewelry, Precious Metals, and Pewter Industries — The full FTC Jewelry Guides, which govern every material claim quoted on this site.
• 16 CFR 23.3 - Misrepresentation as to gold content (FTC Jewelry Guides) — Defines the gold-plate minimum (0.175 microns), heavy gold electroplate (2.5 microns) and the gold-filled 1/20th-by-weight threshold.
• 16 CFR 23.4 - Misuse of the word 'vermeil' — Vermeil requires a sterling silver base, gold of at least 10 karat fineness, and a minimum 2.5 microns throughout.
• 16 CFR 23.5 - Misrepresentation as to silver content — 'Sterling' requires at least 925/1000ths pure silver; 'coin silver' at least 900/1000ths.
• 16 CFR 23.11 - Misuse of 'corrosion proof', 'rust resistant', etc. — Governs the durability claims routinely made in jewelry listings.
• 16 CFR 23.12 - Definition and misuse of the word 'diamond' — Sets when a laboratory-created diamond may be called a diamond and what disclosure is required.
• 16 CFR 23.19 - Definitions of various pearls — Distinguishes natural, cultured and imitation pearls.
• 16 CFR 23.20 - Misuse of the word 'pearl'
• 16 CFR 23.23 - Disclosure of treatments to pearls and cultured pearls
• 16 CFR 23.25 - Misuse of 'ruby', 'sapphire', 'birthstone', 'gem', etc. — Governs how created and imitation stones must be described, including birthstones.
• 16 CFR 23.27 - Misuse of 'real', 'genuine', 'natural', 'precious'
• ASTM F136 - Wrought Ti-6Al-4V ELI alloy for surgical implant applications — The standard behind 'implant grade' titanium. A listing that names it is making a checkable claim.
• GIA Gem Encyclopedia and gemological education — Reference source for gemstone hardness, species and treatment terminology.
• Amazon Associates Program Operating Agreement — Why every price on this site is pulled live and date-stamped rather than typed in.

The figures these establish

The specific numbers that recur throughout this site, and where each comes from:

• 0.175 microns - the minimum gold thickness for a piece to be described as gold plate or gold electroplate. 16 CFR 23.3.
• 2.5 microns - the threshold for “heavy gold electroplate”, and the minimum thickness required for vermeil. 16 CFR 23.3 and 23.4.
• 1/20 (5%) of total metal weight - the gold-filled threshold. 1/40 is rolled gold plate. 16 CFR 23.3.
• Sterling silver base, 10K+ gold - the other two conditions for vermeil. 16 CFR 23.4.
• 925/1000ths - the minimum purity for “sterling” or “solid silver”; 900/1000ths for “coin silver”. 16 CFR 23.5.
• Lab-grown diamond disclosure - when a laboratory-created stone may be called a diamond, and what disclosure is required. 16 CFR 23.12.
• ASTM F136 - the wrought Ti-6Al-4V ELI specification behind “implant grade” titanium. This is the standard a listing is referencing when it says G23 or Grade 23.

What is not a source

Three categories of thing that appear elsewhere and deliberately do not appear here:

• Our own testing. There is none. We have not handled any product on this site.
• Aggregated customer ratings. We do not restate a retailer’s star rating as if it were our finding, and we publish no ratings or reviews of our own.
• Brand marketing material, except as evidence of what a specific listing claims about itself - which is a different use from citing it as a fact.

Terms with no source, because none exists

Part of what this site does is identify claims that have nothing behind them. These appear constantly in jewelry listings and none of them has a definition, a threshold or a certifying body in the United States:

• “Hypoallergenic”
• “Surgical steel” (as distinct from a named grade such as 316L)
• “Non-tarnish”
• “Waterproof” as applied to a coating
• “Titanium steel”

The absence of a source for these is the finding. How to read a jewelry listing covers what to look for instead.

Verification

Every URL on this page was requested and confirmed to resolve on 7 September 2026. If one breaks or a standard is revised, tell us at the address on the contact page and we will update it.