Coin experiment gives surprising results!

Yeah, I'm going to try the water softener trick, suggested by Roman Collector, on my next coin. This time I 'm going to use a spoiled 2014 sheild penny that has a lot of original luster. I'm curious how the luster will be affected.....Spark.

btw, my nickname is "Spark", but I answer to Spark-o, Spark-o-matic and the dinner bell.

 

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I agree.

And I try my hand at it myself now and then. After decades of experience on when and when not to try, I find I still ruin about 20% of them.

 

My apologies to anyone waiting for my next experiment results....I've had a delay with supplies. I will post asap when done...Spark

 

As others have mentioned this is what ancient collectors often call "electrolysis" and is a common technique though usually it's a last resort sort of thing.

I doubt it would work for copper but a well known technique for cleaning silver ancients is electrolytic reduction. You MUST have all loose dirt off the coin before starting, I recommend a quick acetone dip even. You take a small cup or dish, fold aluminum foil several times over until you have a few layers the size of the container and then abrade the surface of the foil using steel wool, sandpaper or similar and place the foil in the container, folding the top layer over the coin and getting as much of the surface area of the foil touching the coin as possible. Then make a weak(2-5%) citric acid solution(or use a lemon) and mix with boiling salt water, a tablespoon or two of your acid solution per cup of saltwater and dump into your container. Watch the coin religiously checking at least every two minutes. The silver sulphide compounds that tend to make up the majority of encrustations on silver should react much quicker with the solution thsn the silver of the coin and unless there's an alloy mixing problem it should not eat into the coin surface much if at all but can remove luster in some cases.

I recommend trying on some heavily(perhaps artifically) toned junk silver first before you ruin a good coin, though my first try with it was on a very rare ancient and it turned out just fine.

 

So basically, crack out an early PCGS-graded American Silver Eagle with color? Right. Got it.

 

Of course one could use platinum electrode points. The contact should be microscopic if at all at low voltage. .....a little expensive unless you work within a lab Jim

 

The next question is, is the coin stable? I've been burned a few times on coins that changed for the worse after I bought them.