I apologize if this has been asked before. When is a coin considered a copper coin, and when is it considered bronze? Okay, Early American Coppers are 100% copper. Yes? Many times I see U.S. Cents before 1982 (with exceptions) referred to as "copper." Yet the Red Book describes these as Bronze due to having a 95% copper content. I've seen Canadian Large Cents from Victorian Years called both copper and bronze. I think they are 95% copper. Any thoughts on this are appreciated.
Bronze is an alloy, primarily copper with about 12% tin. Copper content of 95%+ is considered copper. When copper is alloyed with zinc, if the zinc content gets too high it is considered brass. I think this is right, long time since I was at school
Thanks for this. As far as alloys--never learned these in school. And have forgotten most of what I learned in school.
Yes, IMHO, early American coppers should be referred to as copper as that is the primary composition. Because copper is soft there always has to be a binder metal. Lincoln cents should be referred to as bronze as that is the metal mix of copper and tin. This mix, when not done correctly causes "Woodies" and brass streaking on these coins. After 1982 it all changes to copper plated zinc. Sometimes the terms are interchanged without proper knowledge and even some of the earlier references get it wrong.
This explains something to me. My "cull" Early Coppers have so many different dings, scratches, flat rims, corrosions, and other yucky stuff. My aged and well-worn Lincoln cents don't seem as beaten up.
Tougher times those early coppers saw for sure. But a lot of culls were also found/dug coins by metal detectorists. A lot of times these would end up in dealers bargain bin boxes, bought on the cheap and used for fillers in collections by those of modest means.
Even though "copper" coins can never be perfectly pure metal, they do seem to be softer and redder than coins deliberately alloyed with enough tin to be called bronzes. Old bronzes usually look browner in color than purer copper coins. A couple Russian/Soviet 5 kopecks (1858, 1924) to show some nice big coppers. Asian coins are a bit more complicated. They were made of a crazy mix of elements, including coper alloyed with lead, zinc, tin, and antimony. The composition would vary from province to province depending on the quality of the copper source available and how much other metals would be used to reduce costs. I think these tend to be called "copper" in general without reference to which specific alloy composition was used, which is hard to tell non-destructively. Some Northern Song Dynasty coppers: (1101-1117)
