To clean or not to clean and how?

[bottlecap4u]

Pick at the back with a toothpick, otherwise don’t mess with it. Nice coin!!

 

[too_pointer]

You have an ( after picture) ?
too_

 

[2CentSalm]

In 2016 our town did a main street and sidewalk tear up. I was out there every evening after the work crews left. I made a lot of great finds, and some artifact finds that were pretty cool and those now reside at the local museum. One coin stood out to me as being in rather good shape for a dug coin. Turned out to be a 1918 D Buffalo. The detail on the coin is in really nice shape compared to the other buffalos I have found where the date alone was wiped off the coin. This one looks nice, but it is black in color. My question is leave it alone or clean it to where it looks like a normal nickel. This is a key date coin so I want to preserve it's value.View attachment 609212View attachment 609213

As a numismatic collector, I say no to any cleaning except with Acetone and distilled water. Cleaning any coin will devalue the specimen and deem it as Post Mint damage or environmental Damage.

 

[Pete e]

I found this interesting link about cleaning coins and it applies to other copper alloy artifacts as well.

The good thing about the link is that the author provides excellent before and after pics of each stage...

I have tried the method on a few copper alloy coins/artifacts and I have been happy with the results so far ..

Rare Coins & Relics - Cleaning Coins: Alkali Washing with Sodium Sesquicarbonate

The absolute safest and most effective method for cleaning coins found metal detecting. You start with a solvent polarity ladder of Distilled Water, Acetone, and Xylene. Transitional steps include Sodium Sesquicarbonate or Sodium Thiosulfate. An application of VERDI-CARE™ as a final measure. ProDe

www.prodetecting.com

That said, with more valuable coins, depending on their condition, I would take professional advice before doing anything....