CPM Forum
Canadian Notes => Bank of Canada Notes => Topic started by: Tom W on May 27, 2011, 08:27:20 pm
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I would like to know how much gold (or other precious metal) in grams (or milligrams) is present in Canadian dollar bills.
How much gold is present in the little square in these (now out of circulation) 20, 50, 100 and 1000 dollar bills?
http://www.cdnpapermoney.com/images/Birds/1991_20f.jpg
http://www.cdnpapermoney.com/images/Birds/1988_50f.jpg
http://www.cdnpapermoney.com/images/Birds/1988_100f.jpg
http://www.cdnpapermoney.com/images/Birds/1988_1000f.jpg
How much gold is there in the holographic and security strips of these current notes?
http://upload.wikimedia.org/wikipedia/en/7/76/Canadian_bills2.jpg
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My first guess is probably none... That stuff isn't likely to be something as simply as gold leaf but rather a highly engineered synthetic film.
Of course, one could always check by putting a sample under a scanning electron microscope and getting an analysis. That would tell you if there's any gold there at all.
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I don't think a scanning electron microscope would be used for the determination of elemental composition. I never used a SEM but I seem to recall that gold would actually be used to coat a sample to be analyzed by SEM.
I think X-ray fluorescence spectrometry (XRF) would be more appropriate, or X-ray diffraction spectrometry. Both are kind of expensive, but if someone can remove a bunch of those gold-coloured holograms from Bird notes, there should be enough material for an analysis. But, of course, the Bank of Canada might have something to say about the tampering of their notes, lol.
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That's basically what I was referring to... On at least the two that I've seen, SEMs have the ability to perform some form of spectrometry to analyze the elemental composition of the surface of an object. There's no point in getting a high-res image of the thing... that won't tell you anything. But an element-by-element analysis of the surface will tell you whether or not any gold is present.
I'm sure there are other means of achieving the same thing, but the point is, there are ways of doing it.
A few years ago, I had a loonie I suspected to be fake. I brought it to the science department at the local university and found someone who had an SEM. We put the loonie under the scope, did an analysis of it, and determined that it was made of all the right elements in roughly the right ratios, so it was more than likely authentic. We even made a gouge in the surface to expose the metal at the core and found the same results. I don't recall the exact name of the method of analysis we used, but I believe it was a form of spectrometry.
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It was probably called XRF. I thought the strips are made from tin like tin foil. I did test one, one time I used a high powered magnet to see if it would come off but it was not attracted to it.
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Thank you for your answers. Although I wasn't expecting answers suggesting using electron microscopes or spectrometry. Perhaps someone already knows because they asked the Bank of Canada or the company that actually prints the bank notes.