Dave Baldwin writes:
I would like opinions/comments on what 'bronze' means to numismatists. I recently had
the opportunity to have several medals subjected to xray flourescence and the results are rather
interesting. A few did show as 100% copper but most were not.
Bronze pieces are usually described as chocolate brown with copper pieces being more red. But
two Buchanan Residence medals came up with the redder piece being 99.46% copper, .32% platinum,
.17% zinc and the brown piece 99.68% copper, .22% platinum. And bronze is usually described as an
alloy of copper and tin yet none of the ones tested showed any trace of tin. Small amounts of zinc
were found and almost always some platinum.
Online searches for definitions of bronze are pretty inconclusive and it seems the term copper
alloy is preferred. So as numismatists what do we mean by bronze and how is that determined? I have
also seen the term 'bronzed copper', is that bronze or a copper piece with bronze plating?
Any help would be much appreciated.
That's a great, fundamental question in numismatics. I'll look forward to
compiling reader thoughts for next week's issue. I asked Dave for some more information and
image, which he gladly provided. -Editor
Medal 1: 99.73%copper, .2% zinc
Medal 2: 97.18% copper, 2.78% zinc
Medal 3: 99.68% copper, .22% platinum
Medal 4: 99.46% copper, .32% platinum, .17% zinc
Medal 5: 99.54% copper, .32% nickel
Medal 6: 100% copper
Medal 7: 99.11% copper, .4% iridium, .31% nickel
It is interesting being able to get accurate descriptions for the tokens and medals. One piece
that was described as "nickel" turned out to be 100% silver although it did not look like
it at all. And it is free! I have a contact at a precious metal recycler and every few months I
take a handful up to put through the machine Takes about 15 seconds and he says the machine is very
accurate. Next time I am going to take one up he has done already to see if the reading is the
Wayne Homren, Editor
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