How to identify a coin

Step by step

1. 1

   Read the legend exactly as written

   Copy the inscription letter by letter, including abbreviations and any letters you cannot read, marking those with a dot. Do not translate or normalise it yet: the spelling itself often dates the issue and names the authority.

   • Which script: Latin, Greek, Cyrillic, Arabic, Han, Devanagari?
   • Is there a ruler's name, a title (REX, IMP, D G) or a state name?
   • Are letters retrograde, ligatured or abbreviated in a period-specific way?
2. 2

   Identify the issuing authority, not the modern country

   Coins belong to the state or authority that struck them. A 1915 corona is Austro-Hungarian, not Austrian or Hungarian; a 1790 thaler is from a specific German state, not from Germany.

   • Ruler's portrait or name and their reign dates
   • Heraldry: eagle, lion, arms, shield quarterings
   • Whether the authority is a kingdom, city, colony, empire or republic
3. 3

   Establish denomination and date

   The denomination may be written out, abbreviated, implied by size and metal, or absent altogether. Dates may be Gregorian, regnal, AH (Hijri), Buddhist era or absent — record the date in its original form first, then note the converted equivalent separately.

   • Numeral plus unit, or a value symbol
   • Calendar system in use and whether the date is of striking or of authorisation
   • Undated issues: date the type by ruler, style and reference, not by assumption
4. 4

   Measure before you match

   Diameter in millimetres, mass in grams to two decimals, and thickness are the cheapest evidence available, and they separate genuine types from imitations, restrikes and later copies far more reliably than appearance does.

   • Diameter and mass, measured, not estimated
   • Edge: plain, reeded, lettered, decorated
   • Die axis (rotate the coin about its vertical axis and note the angle)
5. 5

   Find the mint mark, privy mark and engraver's initials

   Small marks near the date, in the exergue or beside the design usually name the mint or the officials responsible. They are what distinguishes otherwise identical types, and they are exactly where invented information tends to creep into online listings.

   • Letters or symbols separate from the legend
   • Initials under the truncation of a bust
   • Mint marks change over time: check the mark against the date, not in isolation
6. 6

   Match to a catalogue reference and record the disagreement

   Only now compare with a standard catalogue, museum record or archive entry. If two references classify the same coin differently, record both readings with attribution rather than choosing the more convenient one.

   • Cite the catalogue, its edition and the number
   • Note anything the source does not cover
   • If nothing matches, the answer is “not yet identified”, not the closest-looking type

Worked examples from the catalogue

Each example is a real catalogue record with its sources, confidence level and the questions still open on it.

Common mistakes

• Treating a modern restrike, a replica or a jewellery copy as the original type — these are usually marked, lighter, or off in diameter.
• Reading a regnal or Hijri date as a Gregorian year.
• Assuming a mint mark from a list without checking that the mint was operating in that year.
• Cleaning a coin before it has been examined: cleaning destroys the surface evidence identification depends on.
• Filing a coin under a modern successor state, which hides the historical context that explains it.

Identification tells you what a coin is. It does not tell you its grade, its rarity or its value — those are three further questions, answered by different evidence, and this catalogue deliberately does not answer them.

Practise on these records