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<p>[QUOTE=&quot;GDJMSP, post: 2872339, member: 112&quot;]The answer to the basic question asked in this thread - &quot;Xylene&#039; - Is it a suitable product for use on Bronze AND Silver coins?&quot; - is quite simple. The answer is yes. But whether or not using xylene will be, shall we say, effective or not, well that depends on what you are trying to remove it. Some things it will dissolve and safely remove them from the coins. On other things it will have no more effect than distilled water will have on them - because it will not dissolve those things. In fact sometimes distilled water will be more effective than xylene because it will dissolve some things that xylene will not. But in any event there is only a short list of what xylene will remove.</p><p><br /></p><p>The subject of bronze disease and verdigris - that is another matter entirely. But it&#039;s really pretty simple. What it boils down to is this - corrosion, specifically the corrosion of copper. When copper corrodes the metal itself is eaten away just as any metal is eaten away when it corrodes. And what the copper turns into as a result of corrosion is the green stuff. That green stuff is verdigris. Verdigris does not cause the corrosion, verdigris is the result of corrosion. When verdigris is fresh it can be almost powdery in nature, but over time it can and often does change sometimes even becoming quite hard. Other times it may even mix with liquids, water for example, and become runny and leave green streaks across the copper. Just like you see rust streaks on iron or steel, you can see verdigris streaks on copper.</p><p><br /></p><p>With coins, when you see the green stuff it is because the copper in the coins is corroding - it&#039;s just that simple. And it doesn&#039;t matter if they are very old or ancient coins, or the most modern. If they contain copper and that copper corrodes verdigris is formed - period. This is a simple fact - not an opinion.</p><p><br /></p><p>Now they, meaning moderns and ancients, may look different and feel different but that is merely because of the changes that the verdigris has undergone over time as a result of what it has been exposed to over the years, as well the lack of exposure, depending on the case at hand. But in the beginning it is all verdigris. </p><p><br /></p><p>Can the chemical composition change ? Of course it can because the verdigris can mix with other things as a result of exposure to them, or not change because it wasn&#039;t exposed to them. </p><p><br /></p><p>Where people get confused when talking about verdigris and bronze disease is because they think it&#039;s two different things. No one would ever say that a modern coin, or even one that is 200-300 years old has bronze disease. But they would say that coin has verdigris on it when they see the green stuff. </p><p><br /></p><p>With ancients they refer to the green stuff as bronze disease because that&#039;s what they&#039;ve read in books, or been told by knowledgeable people all their lives. But bronze disease is nothing but a colloquial term developed years ago to describe verdigris on ancient coins. And yes, it can be very hard, very crusty, seemingly almost impervious at times, and yes it can even change colors sometimes. But this is merely because of what happened to the verdigris over a long period of time. But in the beginning, when it first formed, that&#039;s all it was - verdigris. The very same verdigris you see on modern coins.</p><p><br /></p><p>So what will remove verdigris ? Well you can remove it by hand and force if you wish but that often results in damaging the coin. In my life I have known of 2 and only 2 liquids that will remove it. One is Biox, a commercial product you used to be able to buy (may still be able to for all I know) and it would remove it. But, it would also damage the coin in the process. The other is Verdi-Care, (what was originally Verdi-Gone), and Verdi-Care does not damage the coin. But according to its maker it does leave a protective film on the coin. Verdi-Care will dissolve verdigris, to a limited degree anyway. Coins with minor verdigris it will remove most of not all of it. If the coins have a lot of it on them, typically only some is removed. </p><p><br /></p><p>But acetone, water, xylene and nothing else that I&#039;ve ever heard of, besides some acids, will dissolve verdigris.</p><p><br /></p><p>The argument that verdigris and bronze disease are two different things is a very old one. But they aren&#039;t two different things, in the end they are the very same thing - the corrosion of copper and its result. That&#039;s all it is.[/QUOTE]</p><p><br /></p>

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