Cleaning a coin, what have I formed?

I was recently given some no-date Buffalo Nickels. I kept trying to find a way to clean it just to see the dates (these are some pretty banged up coins, for those of you wondering). Well, all I did was sit the nickels in a little bit of vinegar to begin eating at the coins (it's working so far! ). I went to look at the coins to see their progress, and noticed that the vinegar was turning a slightly blue color. I figure the acid is reacting to something in the composition of the nickels, but I am unsure what part would be creating this. So I have two questions to ask you:
1. What is creating this bluish tint in the vinegar?
2. What is this blueish color? I think it is a chemical compound, but want some expert input.

 

Log in or Sign up to hide this ad.

Here is the pic of what has been formed.

 

Nickel(II) acetate (Ni(CH[SUB]3[/SUB]COO)[SUB]2[/SUB])is an inorganic compound of nickel and acetic acid (vinegar). This inorganic compound is usually found as the tetrahydrate. It is used for electroplating.

Nickel salts are carcinogenic and irritate the skin.

Wouldn't play around with that stuff if I were you.

 

...And just what did the coins look like after their bath?

 

Well, don't drink it or swim in it.

Yes, soluble nickel salts are toxic. But you're dissolving scant milligrams of nickel when you do this. It's really nothing to panic about.

 

Just got back from washing my hands for about five minutes. Thanks for telling me, I had my hands right in that stuff before I noticed it was bluish.

 

I'll post pics when they are finished. I think it'll be around Sunday. Maybe Monday if I want to continue testing. I can tell one is a 1929, two are beginning to show dates, and one is still unreadable.

 

Primarily copper acetate, nickels are 75% copper as I recall.

 

Whoops, I always forget that nickels really are not all nickel.

 

[QUOTE I noticed it was bluish.[/QUOTE]


I have many friends that are bluish, but not orthodox.

 

Yep... Mostly Copper Acetate.

 

Actually you could just put a drop on the place where you want to bring out the date.

 

:too-funny::too-funny::too-funny::too-funny:

 

Date less coins are forever dateless. I picked up many as a young lad and cast them away without a thought. You folks would do well too to do the same. Dateless coins with resurrection Voodoo will never be collectible.......

 

I've a few of those too but you must insert a 'J'........



:too-funny::too-funny::too-funny::too-funny:[/QUOTE]

 

[/QUOTE]

Blujish???!!!

 

Rotfl..........

 

Can that happen? Alone, nickel displaces hydrogen from acids, but copper doesn't. Acetic acid isn't much of an oxidizer or complexing agent. Is there something that lets the nickel bring the copper "along for the ride"? Does it somehow allow dissolved oxygen to attack?

 

I'd trust the chemist Badthad

 

Oh, I do -- I'm just begging for an explanation.