How to Identify Metal Detecting Finds: Measure First, Never Clean

Because the surface is the object. On a coin, the original patina and the fine detail of the strike are what a grader assesses, and any abrasive or chemical process leaves marks that are obvious under magnification even when they look fine to the eye. Collectors describe a cleaned coin as damaged, and damaged is a permanent category, not a temporary one. The difference between an uncleaned and a cleaned example of the same coin is frequently most of the money.

On an older or archaeological find the stakes are different but the answer is the same. Corrosion products, soil adhering to the surface and the pattern of wear all carry information that identification and recording depend on, and a recording scheme wants the object as it came out of the ground. If a find falls within whatever treasure or portable antiquities scheme applies where you live, report it and do not clean it first. Stabilise it by keeping it dry, and let a conservator make that decision.

Weight and diameter are the fastest route to an identification on a coin sized object, because they are published, they are precise, and they do not depend on being able to read a worn face. The figures below are the United States Mint published specifications for circulating denominations and for the pre-1965 ninety percent silver issues, which are the ones detectorists most often need to separate.

Look at the back and the edge before the face. A button has a shank, a shank scar or a soldered loop, and a flat-backed button often carries a maker name in an arc. A token is usually thinner and softer than a coin of the same diameter and frequently carries a business name rather than a ruler or a state. A trade weight is disproportionately heavy for its size, which is exactly what a scale reveals in two seconds. Lead is soft, dull and marks with a fingernail, which is why lead objects are often misidentified as heavily corroded silver.

Target ID is a clue here too, though a weak one. A conductivity reading tells you where an object sits in the ordering and nothing about what it is, which is the argument made in the discrimination guide and Use it to narrow, never to conclude.

In roughly this order: your local club, which contains people who have dug the same ground for decades and will recognise a regional token on sight; the recording officer or finds liaison service for your jurisdiction, where one exists; a local museum or historical society; and the published reference books and online databases for the specific category. Joining a club is the shortcut here and it costs less than the books.

If a find falls within a treasure or portable antiquities scheme, report it within whatever period that scheme specifies, and report it uncleaned. Reporting is not optional where it applies, and the general shape of the major regimes is set out in the laws and permission guide. The details vary by country and they change, so read the current text for your own jurisdiction.

Dry, individually, and separately from each other. Loose finds tumbling together in a pouch abrade each other, which is a slower version of cleaning. Cardboard Cardboard Coin Flips, 300 in 6 sizes at $9.50 hold a coin flat without the surface rubbing, and BCW Quarter Coin Tubes, 10 pack are fine for bulk clad where nothing is at stake. Keep iron away from everything else, because active rust migrates.

A Digital Pocket Scale, 200 g by 0.01 g reading to 0.01 grams and the Illuminated 30x and 60x Jewellers Loupe are the two tools that do most of the work, and a Coin Microscope with Weighing Scale at $49.99 is worth it if you are sorting a lot of small detail. For working out whether a silver find is worth grading at all, the silver coin melt value calculator gives you the floor price, and the coin find value calculator totals a season. Melt value is a floor and not an estimate of collectable value, which is precisely why cleaning is such an expensive mistake.