How to Clean Coins Found with a Metal Detector

Hello everyone and welcome back to our blog posts on metal detecting, in this article we have a very quick no-nonsense guide on how to clean your coins found with a metal detector, particularly hammered coins.

Buried Coins

Silver Hammered Coins

In the image you can see three silver coins the first coin is an Elizabeth I three pence that i found metal detecting and the second coin in the middle is a James II that I bought for five pounds in a coin bundle and the final coin is a James I quarter. Coins are ranked from best to worst in terms of how someone has cleaned them in the past, but we will get into that shortly.

How not to clean a coin

Do This

As difficult as it may be when you’re out in the field, try and leave your coins to the end of the day before cleaning, all you need to do is let your coin soak in warm soapy water and then dab dry with a tissue paper or better yet leave to air dry repeat this as many times as it takes to remove all the residue from the coin.

Coin in field

Museum Quality

Coins that are of museum quality that pass new routes of research are now shiny and scratched you may think my Elizabeth I coin on the left needs a good clean and you may if this was yours want to soak it in lemon juice put it between some foil or get some of the pink stuff and scrub it with a toothbrush but cleaning with such methods will completely devalue your silver coins losing 30% value at least, so please ignore all the videos out there that use electrolysis, scrubbing or laying them in acidic liquids.

Elizabeth I

James II

The James II coin however, in the middle of the image has an extremely patchy toning from where the owner had scrubbed all the value away shortly after he found it, the natural patina that this coin had gathered is now very patchy and it’s obvious to see the parts where they have scrubbed it. Most of the clean parts have made the coin extremely shiny and thus I was able to buy this coin in the job lot for only £5.

James I







This is something known by most numismatist’s, a person who collects and studies coins. It is incredibly sad to see coins that have been found and look like they’ve had ten rounds with Mike Tyson with his new Brasso gloves on, completely silver scratched. Attempting to clean coins without a little knowledge you could be ruining and devaluing your hammered coins without realising. Just as a disclaimer this is my own view and what I have learned during my time metal detecting and buying and selling to many knowledgeable dealers and all advice on how to clean silver hammered and early milled coins.

Hammered Coins

Don’t Do This

Let’s look at what you shouldn’t do, I see hundreds of detectorists on YouTube who find hammered coins in clots of earth covered in mud where they have been sitting for hundreds of years and the first thing they do is smear the dirt off the coin so they can see the coin itself, but this is going to cause damage to the coin, some coins tone differently in different soil conditions and some people try to scrub the coin to try and get the dark patina off the coin so you’re left with a very shiny unattractive clean coin so here is a little advice from me.

Coins in Soapy Water

Field Rubbing

Field rubbing the coin’s surface instead of dabbing can completely devalue the coin and your ability to sell it on in the future without having to make a note to the seller that it has been once cleaned before, rubbing coins can also leave nasty hairline scratches and marks all over your coin rendering them ruined in some extreme instances it is completely heart breaking as a collector of hammered coins to see some rarities found detecting that are completely ruined by incorrect cleaning methods.

Hammered Coin Museum



Elizabeth I

Elizabeth I coin I found has been soaked in hot water and dab dried with tissue and is in the exact same condition as I found it, but I have successfully removed all the dirt without removing anything else from the coin and this is the correct way to clean your hammered coins.

This is a common coin found with a metal detector, my first ever hammered coin was found in Shropshire and I will never forget what a great feeling that was.

James II

James I

Now, the final coin has been cleaned to death previously it is shinier in the hand and to a collector of coins this coin would stick out like a sore thumb as being heavily cleaned to the point where many collectors wouldn’t want such an example, I didn’t realise how clean it was when I bought it and for the price I paid I wasn’t bothered, a great example of how all coins shouldn’t be treated and how it can affect the value.

So, there we have it I hope you enjoyed reading our short article on How to Clean Coins Found with A Metal Detector, this gives you some clear knowledge on how to handle your detecting finds. We metal detectorists have an important part to play in preserving historical coins and artifacts for future generations to enjoy and understand how people lived in the past. Our heritage.