Message:

<p>[QUOTE=&quot;-jeffB, post: 2501921, member: 27832&quot;]I&#039;m pretty sure this isn&#039;t true.</p><p><br /></p><p>If those sulfur atoms only grabbed onto silver atoms that are on the surface, and didn&#039;t dislodge those silver atoms from their position in the metal matrix, <i>maybe</i> you could do a fully reversible reaction. But a layer of silver sulfide thick enough to cause interference effects has already dug ten or more atoms deep into the coin&#039;s surface. That&#039;s not very deep at all, but when you remove that layer, those silver atoms don&#039;t return to their original position -- they fall off, although maybe a few randomly reattach to the surface. Repeat that process, and eventually you&#039;ll have a dead-looking coin, no matter how light the toning or careful the &quot;conservation&quot; at each step.[/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