Coin Authentication Checklist
Verify these points before purchasing a Japanese antique coin. The three categories — Visual, Physical, and Provenance — help reduce the risk of acquiring counterfeits.
7 critical items not yet verified
- -Characters and designs are sharp and clear
- -No unnatural seam lines along the edge
- -Weight is within ±3% of the standard specification
- -Diameter is within ±1% of the standard specification
- -Does not react to a magnet (for gold, silver, copper coins)
- -Seller's feedback and track record verified
- -Asking price is not drastically below market
Visual Inspection
Cast counterfeits often show blurred or poorly defined details
Mold-cast fakes typically show a faint seam line around the rim
Cleaned or artificially toned coins display unnaturally even brightness
Genuine casting imperfections follow recognizable patterns
Physical Measurements
Use a precision scale accurate to 0.01 g for reliable results
Measure with calipers for accuracy
Counterfeits often show uneven thickness across the planchet
Au, Ag, and Cu are non-magnetic. Magnetic response suggests an iron core
Provenance
New or low-feedback sellers warrant extra caution
NGC / PCGS / JNDA holders provide strong authenticity assurance
Auction catalog entries or dealer receipts serve as provenance
Prices far below market value are a major red flag for counterfeits
Want to learn more?
Our Counterfeit Detection Guide covers the main types of fakes and the techniques experts use to identify them.
This checklist is provided for reference only. For high-value acquisitions, always seek an independent professional authentication.