Error coin field notes
Short practical lessons for reducing false attributions and preserving evidence.
Why “No Mint Mark” Usually Is Not an Error
Many Philadelphia circulation coins were intentionally issued without a mintmark. The date, denomination, proof status, and normal mint policy matter more than absence alone.
The One-Photo Error Coin Problem
A single close-up hides the host coin, edge, opposite face, scale, and metal-flow evidence needed for identification.
A $50,000 Asking Price Is Not a Coin Value
Unsold marketplace prices are not comparables. Exact completed sales and matched attribution matter.
Why Color Does Not Prove a Wrong-Metal Error
Toning, plating, corrosion, chemicals, lighting, and coatings change color. Weight, edge, dimensions, and composition evidence are required.
Machine Doubling Versus a Doubled Die
Flat shelf-like strike displacement differs from hub doubling created on the die.
The Full Edge Is Half the Identification
The edge can expose missing clad, seams, reeding, collar effects, jewelry damage, repairs, and edge lettering.
Tiny Die Chips and Giant Price Claims
A named blob or viral nickname does not automatically create rarity or strong demand.
Calibrate the Scale Before Claiming a Transitional Error
A few tenths of a gram can separate compositions, but scale drift, dirt, holders, and tolerance can mislead.
Write Observations Before the Attribution
Describe raised, incuse, missing, displaced, weak, doubled, or altered metal before choosing a category.
Preserve the Old Envelope With the Coin
Old labels, dealer envelopes, receipts, and family notes can preserve provenance even when an old attribution proves wrong.