On Sat, 03 Jul 2004 04:54:31 -0400, Gary Coffman
wrote:

On Thu, 01 Jul 2004 12:26:31 GMT, Seppo Renfors wrote:
Gary Coffman wrote:

On Wed, 30 Jun 2004 14:53:00 -0400, Yuri Kuchinsky wrote:
Gary Coffman wrote:

[snip]

The apparent fact that the Native Americans *didn't* cast native
copper

This is a "fact" only if you disregard all evidence to the
contrary, as you appear to be doing.

Virtually all of the evidence presented to date in this thread is
against casting of ancient Michigan native copper artifacts. If
you have conclusive evidence showing characteristic porosity
in all the items claimed to be cast, if you have evidence showing
a chemical analysis of true alloying between the native copper
and other metals (mainly silver) found with it in the halfbreed
ore matrix, if you have evidence of large numbers of identically
dimensioned artifacts representative of a casting provenance,
etc, then present it. Otherwise you have no case.

You cannot claim "you have no case" UNLESS you prove there is no "true
alloying between the native copper and other metals" and that takes an
analysis of the metals in the artefacts found. It works both ways you
know.

Actually, I can make the claim, because heavily alloyed copper is no longer
native copper.

You are assuming that ALL native copper is of high purity. In fact
much Michigan copper ore is smelted to remove impurities. See
http://www.usdoj.gov/opa/pr/Pre_96/J...95/58.txt.html


What we do know is that ancient Michigan artifacts have been
found with silver inclusions. That precludes the possibility that
they were ever melted.

No, it precludes that item from having been melted only. You cannot
extrapolate that beyond the artefact itself.

It is a conclusive indication for any case where silver inclusions are
found.

We do know that of the artifacts which
have been put forward as evidence of copper casting, all but
one do *not* show the characteristic porosity of atmospheric
melting of copper, and that one does not appear to be a deliberate
casting.

We see TWO artefacts being claimed as being cast - one being conceded
as being cast. We don't know the composition of the metal of the
second artefact to be able to discard it as "not cast".

Neither Tom or I have conceded R666 was cast. We've agreed it shows
all the characteristic signs of atmospheric melting, but it doesn't automatically
follow that it was deliberately cast.

You have claimed it is the sign of "copper" being overheated - ie to
melting point else bubbles cannot form. At the same time you have also
stated the heat source has to be forced air type to get it hot enough
to melt copper.

Copper does not need to be heated to melting for blisters to form.
Please go back and reread Neubauer for examples of native copper
which blistered on annealing *without* being raised to melting
temperature. You can blow bubbles in bubble gum without melting it,
you can do the same in copper. It merely has to reach a sufficient
state of plasticity for the gas pressure from inclusions to deform it
into a blister.

I see those two statements as being inconsistent with each other. If
the Copper was simply hammered and annealed, the temp should NOT be
able to get high enough to cause any bubbling.

Well, then you're wrong.

Gary




Eric Stevens