I just received some Indian Head cents. Two of them look horrible, with a blue-green crusty stuff on them. I was looking around on the internet, and there was an article about cleaning your coins with salt and vinegar, and the importance of rinsing them well, or you'll get--blue-green crusty stuff. I've not ever cleaned any coins before, but since these had already been pretty much ruined, is there a safe way to get the blue stuff off?
Have you tried soaking in distilled water for a few days if it needs to be rinsed well after a vinegar soak?
The coins have VERDIGRIS on them. Cleaning copper with vinegar and salt is the worst thing you can do. While vinegar (acetic acid) and salt (chloride ion) will contribute verdigris feed materials, your coins were most likely just improperly stored. All verdigris needs to grow are air and water (humidity). Light to moderate verdigris can usually be properly conserved with VC, heavy verdigris cannot be adddressed without causing serious damage to the coin surfaces. Most often, it's simply better to just toss the coins and buy new ones without verdigris, depending on the grade of the coins.
