Reply to Thread

Message:: [QUOTE="desertgem, post: 2872292, member: 15199"]How such occur is of course interesting scientifically, especially ancient coins due to the long time period exposure of the regions environment, and sometimes the sometimes questionable composition of metals. But most are concerned more about either how to remove safely if present somehow on ones coins, or how to prevent from occurring.       It is my opinion that for copper/silver composition coins, preventing moisture as much as possible, and not using products with PVC plasticizers. So strongly limit exposure to water and and progenitors of an acidic environment. I mainly collect modern ( post 1800) varieties, and often have purchased some with initial reactions. I have tested both the old product "verdigone" ~past posts here. and the current products and I have found them extremely useful for "conservation" and stabilization. I have only used them on 2 ancient copper containing coins, which were much more corroded than most moderns, and results were much less ( as expected), but better than before, and the coin hasn't resumed such corroding, due to proper storage. With ancient coins, harsher methods of cleaning seems to be acceptable as well as using coating material on the surface of the coin as a preservative that modern coin collectors do not accept, indicating different traditional methodology.[/QUOTE]