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<p>[QUOTE=&quot;-jeffB, post: 2434864, member: 27832&quot;]Sure, nickel is magnetic, and an old Canadian nickel will stick very nicely to even a relatively weak magnet. <i>Cupro</i>nickel, though -- the 75% copper, 25% nickel alloy used in US nickels -- never will. <a href="http://journals.aps.org/pr/abstract/10.1103/PhysRev.38.828" target="_blank" class="externalLink ProxyLink" data-proxy-href="http://journals.aps.org/pr/abstract/10.1103/PhysRev.38.828" rel="nofollow">According to this abstract, you need at least 56% copper to start seeing ferromagnetism &quot;at ordinary temperatures&quot;.</a></p><p><br /></p><p>To be fair, I overstated my case (long ago) when I said &quot;the <i>only</i> way&quot; was chemical tests or XRF. I&#039;m sure the alloys differ in lots of ways -- permittivity (how they react <i>electrically</i> in a magnetic field), conductivity (although to test this you need to dig under the surface layer), stiffness (which would affect their &quot;ring&quot;), and so on. Only scientists and engineers are likely to have the tools and knowledge to take advantage of those, though.</p><p><br /></p><p>Actually, that&#039;s not <i>entirely</i> true. We all have access to tools that do a fairly sophisticated and very quick analysis of size, weight, and magnetic properties. They&#039;re known as &quot;vending machines&quot;, &quot;CoinStar&quot;, and the like. They reject silver pretty reliably; they reject steel and pure nickel coins 100% of the time. Would they reject a silver-composition nickel? Maybe. I&#039;m not sure I&#039;m willing to spend many war nickels experimenting, though. <img src="styles/default/xenforo/clear.png" class="mceSmilieSprite mceSmilie2" alt=";)" unselectable="on" unselectable="on" />[/QUOTE]</p><p><br /></p>

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