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<p>[QUOTE=&quot;Roerbakmix, post: 8397141, member: 100731&quot;]I very much agree with this. Any experienced coin restorer knows methods to (re)tone silver coin. Even the so desired &#039;cabinet toning&#039; can be created, if you know how it works. </p><p><br /></p><p>Methods to detect a recently repatinated coin are <i>smelling </i>and even <i>tasting</i>. </p><p><br /></p><p>Repatinating with e.g. liver of sulphur is easily detected, if you know what to look for (brown / blue patina). Artificial patina caused by exposure to heated elemental sulphur is also (yellow / golden / black / grey patina). </p><p><br /></p><p>I openly share my cleaning methods (search my post history), contrary to most coin restorers. Though this results in less coins sent for restoration, I hope it will result in less coins being destroyed by inadequate cleaning methods (e.g. boiling the coin in sodium bicarbonate + aluminium foil which dissolves the desired silver sulphide patina; immersing a silver coin in ammonia which dissolves the copper; repatinating a coin stripped of its patina with chlorides, which (though resulting in a pretty evenly grey patina), is actually harmful and will result in pitting, etc.)</p><p><br /></p><p>I like to share this example: a heavily encrusted 10 litra of Hieron II, with a thick layer of silver chlorides (horn silver):</p><p>[ATTACH=full]1489957[/ATTACH] </p><p>The coin was then immersed in sodium thiosulphate, which dissolved the encrustations:</p><p>[ATTACH=full]1489956[/ATTACH] </p><p>However, overall, the coin became a bit dull-grey (not unpleasant, by the way). Is this repatinating? I would disagree: a basic understanding of the cleaning process learns that this is in fact a very thin layer of Na3AgS2O32, a relatively stable (and thus protective) patina.[/QUOTE]</p><p><br /></p>

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