Gary Coffman wrote:

On Mon, 05 Jul 2004 01:49:44 GMT, Seppo Renfors wrote:
"Paul K. Dickman" wrote:
Seppo Renfors wrote:
Are you suggesting the "tears" are the result of (A) the pure copper having
been melted (B) because it is pure copper?

They are a result of the small air bubbles trapped throughout the metal
caused by melting it in less than controlled conditions.

I can understand that during a melting process where molecules are at
their most active, some reaction to air and a certain amount of mixing
can occur.

Atmospheric oxygen actually dissolves in molten copper,

Thank you that were the words I was looking for those that equals or
points to "melted".... and this I have no problem with.

[..]


What I find difficult is that an annealing process causes
bubbles -UNLESS it is overheated to a melting point locally. How else
does something get INTO the metal to cause bubbles when it is pure to
begin with?

How about when the native copper was formed?

OH no you don't! You claimed "chemical" remember - not "melted".


Masses of native
copper typically have small inclusions, bits of rock, silver, etc. In
particular, in the Keewenaw range, calcium carbonate inclusions
are common (refer back to the frequently referenced article giving
the geology of the region).

....as I have been suggesting - small pieces made bigger via
melting....

When calcium carbonate is heated, it decomposes into CO2 and
calcium oxide fume. The CO2 will blow a blister if the inclusion is
near the surface of the piece of heated native copper being
annealed.

You have to understand that native copper is chemically pure
(99+%) metallic copper by definition, but it is deposited in a rock
matrix where it is later found and mined. Small inclusions are
common. They aren't *chemically* combined with the copper,
the copper is still pure, but they are *mechanically* combined
with it.

We were talking about so called "native copper" - ie PURE copper. My
pointing to inclusions of all sorts of other imperfections among the
"pure copper" veins has been rejected as it tends to point to a
necessity of purification via melting. Isn't this argument now
supporting my earlier suggestions, previously rejected? You are now
the second person to point to "melting" for the bubble to occur/form.




--
SIR - Philosopher unauthorised
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The one who is educated from the wrong books is not educated, he is
misled.
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