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<p>[QUOTE=&quot;Morgan, post: 76847, member: 3630&quot;]Ahhh! </p><p>Now we&#039;ve stumbled on the problem. The reason most people do not like the golden dollar is it is really, REALLY <span style="color: black"><font face="Times New Roman"><font face="Verdana"><font size="2">susceptible</font></font> </font></span>to toning. The reason why is the oxide formed when the metal reacts with air is dark brown. This stands out significantly on a gold colored coin. With the silver and clad coins the oxide formed is closer to the original color so the initial toning is not as dramatic. People usually refer to this as loosing luster not toning even though they are one in the same.</p><p>&nbsp;</p><p>This is where a sealing coat or airtite is handy. The oxidation process can be accelerated by the presence of vapors in the air surrounding the coin. In your case the wood may be the source of the vapors but I would bet it is the glue used to attach the liner. </p><p>&nbsp;</p><p>Way to many thing can cause problems with vapors but one of the worst is a free chloride ion. This ion is why PVC is so&nbsp; damaging. A free Cl- ion is very reactive and just loves to react with metal. This reactivity is due to the location of the valence electrons and their affinity to develope full electron clouds. This is what actually allows the <span style="color: black">galvanization process. </span></p><p><br /></p><p><span style="color: black">In short a salt ionizes into a positive and negative ion the negative ion forms a compound with the metal and oxidizes the metal. This oxidized metal may stay put and be considered corrosion or it may move. If it moves towards the other metal it can react with that metal as well. Now that the ion is already reacted it may decide that it likes the other metal better. When it drops the first metal ion for the second the first metal becomes deposited on the second. This process is very similar to electroplating and this is what I believe you were originally refering to with this post. As previously mentioned a transfere such as this is very slow and requires a soultion which has disolved salts, source of the ions, present in the solution.</span></p><p><br /></p><p><span style="color: black">I had to geek out as well. Sorry for the length but I hope it helps. Anyway the answer to your toning problem is more than likely the Cl- ion in the glue, most glues have chlorides in them, reacting with the highly reactive alloy used in the the golden dollar.</span>[/QUOTE]</p><p><br /></p>

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