Coin help

[treaser hunta]

I bought some silver coins from a buddy of mine a few years ago they are silver coins from the 1700's and they have not been cleaned. Can anyone tell me how i can do them withought damaging the coins. Also some of them are in bad condition and little black peices are falling off of them. Is this bad and can i stop it?

Treasure hunta

 

[JakePhelps]

You cannot clean teh coin without damaging it, but what you can do is stabalize it somehow. Ask an expert on conservation and they should be able to tell you what to do