[meteorite-list] EBAY Slag for sale

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri, 6 Jul 2007 14:07:27 -0500
Message-ID: <124d01c7c000$e59b9460$3d53e146_at_ATARIENGINE>

Hi, Randy, List,

    Starting out with a big disclaimer that this is
all inexpert speculation, of course, I believe the
source of nickel in Missouri slag meteor-wrongs
could be the mineral millerite.

    Smelting is the reduction of iron ores with carbon
as the reducing agent. Impurities in the ores are
removed by the addition of a flux, usually limestone.
In rural Missouri (and anywhere in the Midwest), it's
pretty safe to say the flux is always limestone.

    The resulting slag will, of course, contain whatever
was in the limestone, particularly if the material likes
to combine with iron. Millerite is nickel sulfide, NiS.

    Quoting the Peterson's Rock and Mineral Guide:
"Millerite is sometimes valued as an ore of nickel
when present in minor quantities in association with
other metallic sulfides in middle-temperature veins,
as in Germany and the massive Sudbury, Ontario,
sulfide complex. Locally it is sparsely distributed
through limestones in central Mississippi Valley
limestone quarries, particularly near St. Louis,
Missouri, and Keokuk, Iowa. At these places
long millerite hairs are found in cavities lined
with crystals of calcite, dolomite, and fluorite. (An
interesting, if improbable, speculation suggests the
original source of this nickel might be a heavy
Paleozoic meteor shower.) Coarser millerite needles
have been found with hematite in Antwerp, New York,
and in Alamos, Mexico."

    The use of limestone flux would likely concentrate
all its nickel in the slag, and you would use more flux
with poor ores, which are the ones likely to be used
in a "backwoods" operation.

    Missouri has a lot of lead/zinc/copper/cobalt/iron
sulfide ore belts, very extensive but low-grade localized
deposits, called Olympic Dam deposits. The iron mine
at Pea Ridge, Missouri, is a known Olympic Dam-type
ore deposit. It would appear that rural Missouri would
supply many low-grade local ores with mixed contents.
(I found lots of references, all far too "geological" for
me!)

    My half-cent's worth.


Sterling K. Webb
-------------------------------------------------------------------
----- Original Message -----
From: "Randy Korotev" <korotev at wustl.edu>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, July 06, 2007 9:52 AM
Subject: Re: [meteorite-list] EBAY Slag for sale


At 14:59 05-07-07 Thursday, STARSANDSCOPES at aol.com wrote:
>I don't know why this slag tests positive for nickel, but it does!


People have been making iron and disposing of the
waste for several hundred years in this area and
much of the US. The most common kinds of local
meteorwrong I encounter are hematite nodules -
iron ore - that weather out of the local
limestone. This stuff has been used as feed
stock for mom-and-pop iron smelting operations in
the Ozarks since the 1800's. As Tom Phillips
said, the processes were not as efficient as
today, so a lot of iron metal was left
behind. People have brought us all kinds of
glassy stuff with metal in it, one of which even had the imprint of a bolt:

http://meteorites.wustl.edu/meteorwrongs/m026.htm


Two months ago a fellow came to my office with
the ugliest 60-lb chunk of iron I've ever
seen. He'd dug it up while "grub hoeing" in
south St. Louis Co. There was no smooth surface,
it was very rusty, and it was full of
cavities. It didn't "look like" an iron
meteorites to me, but I have no experience with
iron meteorites that have been in the ground for
100's to 1000's of years, so I really don't know
what to expect. In a post 2 months ago, Eric
Twelker said "Those of us who are lucky enough to
have hundreds or thousands of meteorites pass
through our hands possess a store of knowledge
that has real value to academics that haven?t had
this experience." I agree, and I wish I had that knowledge!

I neglected to get a photo of the thing. I did a
quick nickel test, though, with one of those
nickel allergy test kits and got a positive
result*. So, I cut a piece off and analyzed it
for the Fe, Ni, Co, Au, and Ir. Strange results:

>Fe 89%
>Ni 600 ppm
>Co 62 ppm
>Ir 1 ppb
>Au 12 ppb

The object cannot be a meteorite because the
concentrations of Ni and Co are 100x too low for
metal in any kind of meteorite. Yet, the
concentrations of Ni, Co, Ir, and Au are all
higher that I would expect for iron smelted from
iron ore. More weird is that the relative
concentrations of those elements (ratios) are not
out of line for an iron meteorite. It's as
though the metal is 1% iron meteorite and 99%
pure iron. I don't know what this thing is.

Similarly, a fellow from Colorado sent this photo
and a small sample a couple of years ago:

http://meteorites.wustl.edu/meteorwrongs/m122.htm

It is also a a man-made piece of iron, but one
with far more Ni and Co than in any iron oxide ore I've ever analyzed.

>Fe 90%
>Ni 2590 ppm
>Co 131 ppm
>Ir <14 ppb
>Au 85 ppb

I don't get it.

Randy Korotev


* Note that the dimethyl glyoxime [DMG] test for
Ni is very sensitive. If it gives a positive
result for 600 ppm Ni, then it is too sensitive
to really be of much use in distinguishing
meteoritic metal from terrestrial metal. A
negative result should be helpful, however, if the test is done correctly.)


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Received on Fri 06 Jul 2007 03:07:27 PM PDT