I oxidized some earrings but some parts just won't oxidized! And now the earrings look awful! Is there a way to reverse the oxidization process? I left the earrings in the sulfur of liver for like 30 min btw. It's driving me crazy!
If there isn't a stone involved you can use a liquid tarnish remover like Tarn X. Sometimes the solder, especially in imported jewelry, won't oxidize because it doesn't contain enough silver.
The coins are probably made of a base metal with no silver or copper content. How thin or thick the discs are doesn't make a difference . Some types metal won't oxidize.