Tom McDonald wrote in message ...

Paul,

I'm getting a good free education in this copper business. I
thank you and Gary for your tutelage.

I don't recall reading anything about, for instance, silver
artifacts in the upper Great Lakes area; but this doesn't mean
it wasn't used. I rather suspect that folks were breaking rocks
to extract copper, and may have discarded as debitage the
non-copper bits.

I'll have to look into this, as it would seem that silver might
have been present in large enough amounts that it might have
wound up in archaeological contexts. And, of course, when white
folks came later to investigate and further exploit some of the
copper deposits, I'd be surprised if any silver were to have
been ignored by them.

Tom McDonald

You're missing my point.
Given that casting pure copper is difficult and produces an inferior
product, the casting of copper, simply to save you time forging, is a fool's
errand.( Any craftsman worth his salt would figure this out by the third
try. )
The only good reasons for doing it, are to make a bigger piece of copper or
to clean the rock out.

Eventually, either of these tasks would lead to noticeable alloying.

I would expect this to show up in a full assay of the artifacts.

I've tried to follow this thread, (well, I wandered off when it turned into
a shouting match) and I've yet to see anything that says that all the
artifacts are 99+% pure copper or , in fact, that any were. I am sure that
some testing must have been done, but I am a metalsmith not an
anthropologist, and the relevant research has eluded me so, I have been
unable to ascertain this one way or the other.

Paul K. Dickman