Mint, refiner, hallmark, and serial-number checklist

What to take away

• Identify the legal mint or refinery and facility before interpreting its mark.
• A list entry for a producer does not certify every product bearing a similar logo.
• Serial format, date, assay stamp, fineness, and location should agree with the applicable specification.
• Package serials and bar serials must be recorded separately, even when expected to match.
• Preserve observable facts and escalate conflicts without altering the item.

Issuer identity

• Legal organization name recorded
• Government mint, private mint, refinery, or brand distinguished
• Physical refinery or mint location identified where relevant
• Current and former logos separated
• Official product page or catalog archived
• Product number, year, size, and finish fixed

Hallmark and assay mark

• Hallmark shape and text match a reliable reference
• Assay mark is not confused with a brand logo
• Metal name or symbol is present where specified
• Fineness format and digits match
• Weight and unit match the product
• Date code is decoded under the correct issuer system
• Marks appear on the specified face and orientation

LBMA's current technical specifications for Good Delivery bars require specified refiner, assay, fineness, serial, and manufacture-date marks and set rules for their clarity and placement. Those rules apply to qualifying wholesale bars, not automatically to retail products.

Serial number

• Every character transcribed exactly
• Letter O and zero distinguished
• Letter I and numeral one distinguished
• Prefix, suffix, punctuation, and leading zeros retained
• Bar, card, certificate, and invoice numbers compared
• Duplicate serial within the holding investigated
• Public posting of complete serial avoided

A serial creates a record key. It does not prevent copying, prove composition, or establish lawful ownership by itself.

Coin marks

• Mint mark location matches the year and version
• Privy mark is expected for the named issue
• Artist initials are not mistaken for a mint mark
• Denomination, date, inscriptions, edge, and rim agree
• Proof and bullion marks are not mixed

The U.S. Mint's mint-mark history explains that mint marks identify facilities and that their use and location have changed over time. A missing mark can be correct for one issue and wrong for another.

Dimensions and appearance

• Bare-item or packaged measurement scope known
• Weight unit and scale resolution recorded
• Length, width, thickness, or diameter measured consistently
• Cast and minted surface expectations separated
• Altered, doubled, soft, or misaligned marks photographed
• Package cuts, reseals, bubbles, or card mismatch recorded

List and accreditation claims

• List owner and exact list name identified
• Metal, facility, brand mark, and effective dates checked
• Current, former, suspended, or transferred status recorded
• Wholesale accreditation not assigned to a small retail unit
• Responsible-sourcing claim kept separate from individual authentication

Evidence file

• Listing, invoice, and payment proof
• Shipping label, receipt, and package images
• Official source with access date
• Raw measurements and instrument details
• Examiner report and custody chain
• Seller correspondence and remedy deadlines
• Acceptance, return, replacement, or quarantine outcome

Stop conditions

Pause when a serial differs, the hallmark belongs to another facility, the date format is impossible, the metal symbol conflicts with the listing, packaging appears replaced, or several measurements remain outside sound limits. Keep the complete order together and contact the seller in writing.

Common questions

Does an official-looking hallmark prove a bar is genuine?

No. It must agree with provenance, product specification, measurements, package, and suitable testing.

Can two genuine bars share a serial?

Practices vary, but an unexpected duplicate requires investigation. Record maker, product, and date context.

Is a missing mint mark always an error?

No. Some issues legitimately lack one. Use the exact year and version reference.

Should I publish a serial to ask for help?

Share only what is necessary through a trusted route. Public serials can expose inventory and aid copying.