Message:

<p>[QUOTE=&quot;quick dog, post: 88078, member: 4093&quot;]The greenish stains on copper coins is a combination of copper salts, the result of chemical corrosion.&nbsp; Copper chlorides are green and brown, depending on the oxidation state.&nbsp; Copper carbonate is green, and the hydroxide is blue.&nbsp; Copper oxides and sulfides are black.&nbsp; Any way you cut it, it seems to me that these copper compounds are not really part of the copper coin anymore.&nbsp; The copper salts are like a layer of chemical debris at that point. </p><p><br /></p><p>I don&#039;t quite understand the use of acetone, unless of course, one is trying not to remove the copper salts and oxidized base metals.</p><p><br /></p><p>If you soaked a highly corroded copper coin in plain water with a tiny bit of detergent, would not some of the corrosion flake off?&nbsp; I&#039;ll bet a sonic cleaner would raise hell with copper oxidation products.</p><p><br /></p><p>What is the difference between a copper coin that was cleaned in 1400 AD, and another cleaned in 1998?&nbsp; One treatment is acceptable, the other not?</p><p><br /></p><p>Signed,</p><p><br /></p><p>Ignorant, and Clearly Not Worthy of Life&nbsp; :thumb:[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in