Eric Stevens wrote:
On Sat, 03 Jul 2004 07:27:39 GMT, Seppo Renfors
wrote:
Gary Coffman wrote:
On Fri, 02 Jul 2004 07:53:30 GMT, Seppo Renfors wrote:
Gary Coffman wrote:
On Thu, 01 Jul 2004 12:10:10 GMT, Seppo Renfors wrote:
Gary Coffman wrote:
On Tue, 29 Jun 2004 07:05:25 GMT, Seppo Renfors wrote:
This has a good story about the Great lakes Copper deposits.
http://www.geo.msu.edu/geo333/copper.html
As that article notes, 14 billion pounds of copper have been removed
from the area since the ancients were working copper there. Let the
enormity of that number sink in. There was an *awful lot* of copper
there in ancient times, much of it easily accessible from the surface.
My main interest was to show the formation of the copper deposits -
the volcanic activity that melted it (and other minerals with it).
Silver is/was found in fair quantities alongside the copper. What
isn't known - because nobody cares to find out, is the composition of
the metal used in the artefacts. It is ASSUMED to be pure copper.
The presence of silver inclusions *proves* the native copper was not
melted after being deposited.
...but only for that piece - not for any other piece. Further more
IIRC there is a method of laminating copper and silver sheet and
carving through one into the other. It is a Japanese technique IIRC.
It requires being heated under pressure, to the point the silver just
starts "sweating" and it brazes the sheets together. So silver in
copper can also be deliberate - as decoration.
It is called silver brazing (or more commonly, but incorrectly, called
silver soldering).
I already said it was brazing. I couldn't think of the specific
decoration name before, but it is used in making "mokume gane" as
found, and originating on samurai sword handles from about 1600 -
1800.
It is a common technique used to join pieces of
copper. Pressure is not required. A temperature in excess of 800F
is required for brazing to occur (by ASTM definition).
Are you suggesting silver "sweats" (forms liquid beads) way below its
melting point?
Native copper is deposited by chemical
means, not volcanic melting and extrusion.
I already posted this earlier. It disagrees with you:
http://www.geo.msu.edu/geo333/copper.html
"chemical" doesn't get a single mention.
Actually, it doesn't disagree with me. It says the copper
was carried in an aqueus solution from great depths
and deposited in the vents, fissures, and voids of the
iron bearing rocks above. The pertinent chemical
reaction involved is
CuSO4 + Fe(Metal) = FeSO4 + Cu (Metal)
If you were knowledgeable of the chemistry of copper, this
would have been obvious to you. If you had read any of the
many geochemical references in the links already provided
in this thread, it would have been spelled out for you in
excruciating detail.
If you had not been so intent on being snaky you would know that
"aqueous" (correct spelling) also means "water like", "watery" as well
as "of or containing water" - therefor it is NOT a clear explanatory
term in itself. Further to that, you would NOT have written that
formula up there - but if you want to argue that particular formula
(A) point out how two solids, suddenly for no given reason, decides to
react and change (B) how they get together in the first place when
they are NOT ambulatory in any way.
http://www.cop.ufl.edu/safezone/prok...5100/eumix.htm illustrates
the basic mechanism. The same kind of thing happens with copper and
silver. The presence of silver will lower the melting point of the
copper and a solid solution will be formed. In the case of copper and
silver
Yeah well..... that isn't really what happened despite there being
several substances in that same solution - as they would all have
ended up in one glorious mix.
http://www.bipm.fr/metrologia/ViewAr...=25&PAGE=41-47
gives the lowest melting temperature as 779.583 plus-minus 0.060 which
is lower than the melting point of either copper or silver.
Many metals will form similar eutectic mixtures with copper,
particularly aluminium and zinc. Some tin-lead solders will form
eutectic mixtures with high alloy steels at quite low temperatures,
which is why at an early stage they stopped soldering identifying
labels onto aircraft undercarriage legs. :-)
Never had anything fly off an aircraft that wasn't intentionally
thrown out of it..... or a mob of disgruntled passengers who decide to
get off in mid air at some 4000 ft as it is the fastest way to the
pub....
Oh and where are these pure iron
deposits, hmmm? It sure as hell would have saved on building blast
furnaces if that existed...
You could have instead pointed to this section in that same article:
"Into the lava flows of Keweenaw, Houghton, and Ontonagon counties
percolating hot waters rising from great depths brought copper and
silver in solution. As it cooled, the waters filled the fissures and
the gas cavities (amygdules) of the lavas (trap rocks) with pure
copper and silver..."
Now here we see something totally different from your "formula". There
IS a mention of a "solution" - most likely the copper portion was
CuSO4.5H2O. There is not a single mention of iron. It also refers to a
heat source - not two ambulatory minerals meeting in the dark for a
bit of kissy kissy, saliva swapping or any other hanky-panky!
So what have we here - we have the result of hot lava, the water
"evaporates" leaving what would be known as, Blue copper, Blue stone
or Blue vitriol (among other things) or CuSO4. Indeed it does exist,
but it isn't your pure Cu, is it.
BUT if I again go back to your "formula" and introduce some "Fe" into
the equation, it has to be as "FeSO4.H2O" solution - 100% water
soluble (used in animal feeds as a supplement). Perhaps more
interesting is the FeSO4.7H2O (copperas), also water soluble, but is
blue in colour similar to copper sulphate and in its solid form it
melts at 64 deg. C! Only problem is that this requires no hanky-panky
at all.... the Fe is pregnant with SO4 already!
I suggest you read the opening paragraphs of
http://www.minsocam.org/MSA/collecto...r/vft/mi2c.htm
Please don't take this as a contradiction. I intend it as an
elucidation. :-)
Actually that is a page I had found... but lost again, as I wanted to
use an image from there to demonstrate the NEED to melt even pure
copper:
http://www.minsocam.org/MSA/collecto...hitepinecu.jpg
A good site!!
So lets add the bit of "mood" to the situation and heat it up with the
cooling lava. The result would indeed be ferrous and cupric oxides,
respectively, giving off water and sulphur trioxide, which combine to
produce a dilute solution of sulphuric acid.
So IF there is either some "copperas" or Ferrous Sulphate Monohydrate
in the CuSO4.5H2O - then one can expect IRON to be present with the
copper - well.... yes but not in the same place by the look of it. But
then if we take both the copper and Iron out of the soup we end up
with H2SO4.... or masses of sulphuric acid (oil of vitriol)! Therefor
Lake Superior is a lake of acid. Then the Moral of the Story is:
don't eat the fish as they will eat your insides out!
Now, I have to admit I have have happily forgotten 99% of what I ever
learned about chemistry (except that needed to make moonshine), but
then again, why on earth am I required to know any of it.....?? To
prevent you getting all snooty by suggesting things??
[..]
Eric Stevens
--
SIR - Philosopher unauthorised
-----------------------------------------------------------------
The one who is educated from the wrong books is not educated, he is
misled.
-----------------------------------------------------------------