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<p>[QUOTE=&quot;-jeffB, post: 1093103, member: 27832&quot;]This is the key assertion, and one that I think we&#039;ll be able to test.</p><p><br /></p><p>I&#039;m becoming more convinced that the primary &quot;wear process&quot; is <i>not</i> &quot;squashing down&quot;, but actual removal of metal. How do we determine which of us is right?</p><p><br /></p><p>I agree with your assertion that coins in XF or AU will usually be within weight tolerance. I don&#039;t think it&#039;s because metal has been &quot;pushed around&quot; instead of &quot;worn off&quot;, though -- I believe it&#039;s because metal has been &quot;worn off&quot;, but it&#039;s not enough to take most coins out of tolerance. (Remember, those two Roosies I posted are actually slightly <i>above</i> specified weight, although still within tolerance -- they could afford to lose more than a coin with &quot;low birth weight&quot;.)</p><p><br /></p><p>I could take a few BU pennies, rub them on cloth for a while, and see whether there&#039;s a demonstrable loss of weight. I don&#039;t know, though, whether that would count as &quot;typical wear&quot;. So, what <i>would</i> constitute a reasonable simulation of typical wear? Carrying them in my pocket with my keys? Running them through the laundry a few times? (I&#039;ve got some very shiny, but very beaten-up quarters that my son forgot to take out of his pocket before laundry day!) I want to do some sort of longitudinal test, following the same coin as it wears, because it&#039;s hard to compare coins that may have started out at different weights. If I can&#039;t do that, I need to get statistics from <i>lots</i> (hundreds) of coins; that would be tedious at best, and I don&#039;t trust my grading skills enough to group coins accurately into grade bins.</p><p><br /></p><p>I&#039;ve got my own ideas as to what goes on as a coin wears, but I&#039;m not nearly so interested in &quot;defending&quot; those ideas as in <i>finding out</i> what&#039;s happening. Now I&#039;ve got some equipment that will let me get the measurements I need. Let&#039;s come up with some testing procedures![/QUOTE]</p><p><br /></p>

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