So I have 4 silver halves and an expanded [. I have a coin purse but it's obviously meant for dollars. Keeping them in there they would rattle around way too much for comfort. I dont want to ding up my expensive shell and set. If I put two Goshman sponge balls in there with them it solves that issue but I can't seem to find out if the red sponge balls would tarnish/yellow my coins. Does anybody have the facts here? I'm not talking experience or what you think, I'm talking if there will be a chemical reaction or not, and If anyone can link me or give me an answer. Google doesn't seem to be able to. Thanks