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Posted 03/17/2016 9:47 pm
jamiep You ask a good question:
The answer depends on how close to perfect pitch you are blessed with. A hot fused Sheffield plate will ring very well and can easily be confused with the real thing. I suspect the frequency has to be somewhere between silver and copper, but I can not discern a difference.
There are Cold fused Sheffield plates which do not ring well at all. These were made by cold rolling the three layers together. They are often encountered partially detached.
Canadian-Banknotes VAM identification would of course work provided the coin is not a forgery made from an original coin. I try never to focus on the details on the die until I rule out all of the transfer methods that can be used to duplicate a genuine coin and I establish how the coin was actually made. If that all checks out then I would go to VAM.
In this case (1881-S) that extra effort of determining which VAM number this was did not seem worth it. I determined the coin was a strike through in under 1 minute anyway using a binocular microscope.
Sheffield plate is an old technology but if it was used today with an advanced die making technique the results would not be readily detectable unless you used a density check like Specific Gravity to determine the alloy was not solid.
Quote:
I was wondering if the ring(sound) of a Sheffield Plate coin would be that of a pure silver coin.
I was wondering if the ring(sound) of a Sheffield Plate coin would be that of a pure silver coin.
The answer depends on how close to perfect pitch you are blessed with. A hot fused Sheffield plate will ring very well and can easily be confused with the real thing. I suspect the frequency has to be somewhere between silver and copper, but I can not discern a difference.
There are Cold fused Sheffield plates which do not ring well at all. These were made by cold rolling the three layers together. They are often encountered partially detached.
Canadian-Banknotes VAM identification would of course work provided the coin is not a forgery made from an original coin. I try never to focus on the details on the die until I rule out all of the transfer methods that can be used to duplicate a genuine coin and I establish how the coin was actually made. If that all checks out then I would go to VAM.
In this case (1881-S) that extra effort of determining which VAM number this was did not seem worth it. I determined the coin was a strike through in under 1 minute anyway using a binocular microscope.
Sheffield plate is an old technology but if it was used today with an advanced die making technique the results would not be readily detectable unless you used a density check like Specific Gravity to determine the alloy was not solid.
