[meteorite-list] "not the best place to hunt meteorites"

From: Michael Murray <mmurray_at_meteoritecentral.com>
Date: Thu, 21 Feb 2008 13:17:44 -0700
Message-ID: <DF052C61-43B0-4B60-851A-02E988AB022D_at_montrose.net>

Hi List,

(This is somewhat of a rehash of information I have posted before)

If the meteorite hunting bug has landed on your shoulder but you
think the area you live in is not the best for finding meteorites,
you should give my hunting method a try. You could be pleasantly
surprised at what you come up with. I went to a local hardware
store a few years back and purchased a shop magnet cane. It has a
wooden handle about 40 inches long with a ring magnet on the bottom
that is sandwiched in between two plates of steel. I also purchased
a couple 2" x 2" x 7mm neodymium iron boron sugermagnets which I
placed very carefully side by side on the trailing edge of the bottom
steel plate. Please note: If you attempt this beware, strong magnets
like that can injure your fingers quite easily. Use plenty of
caution. I put the cane in a vise so it could not move before
attempting to place the first magnet on. The second magnet was a bit
harder to get into place until it got close enough to the first one.

I have drug my magnet cane all over the place, mostly wherever there
are gravels. I have not had any of my finds substantiated by
experts. None-the-less I have come up with some very possible
"suspect" stones. Some are what I believe are irons and some
stonys. A couple suspect stonys I found in dirt not gravels. This
is what leaves me to believe that even if you might not think hunting
in your area would be very good, you may still find that the magnet
will find them anyway. The smaller objects falling to earth most
likely will not penetrate very deep into the soil when they hit.
Some not at all if the surface is somewhat hard. Erosion can also
expose them over time. I live in an area where a river cuts its way
through the valley. I have found that the river gravels contain
quite a few of what I term "suspect" stones. I suppose the reason
for this is that in time, due to constant washing from snow runoff
and forceful rains, a lot of small material finds its way into the
river, including meteorites.

It takes a little time spent looking close at local rocks to get to
where you can pick the unusual out from the rest with any certainty.
Of course, if you live in an area with very few rocks, anything you
pick up might be worth investigating.

After I have drug the magnets for a bit, I clean off anything that
has stuck to them into a fine mesh (window) screen sitting down in a
gold pan. I put water in the pan so it covers the material. I then
wash the materials vigorously in order to get rid of the dirt and
fines, which are usually magnetite. Then I screen the material again
through a 1/4" mesh screen. That lets me look at similar sized
pieces less than 1/4" by themselves, and then also those larger than
1/4" that have been separated by the screen by themselves. I will
keep some water in the gold pan with the smaller material and do what
is known in the gold panning world as a blueberry bounce. That moves
the heavy material to the one side of the pan and lets me see any
iron or metal fairly easily as otherwise those pieces might remain
buried under other lighter weight stones. Then I can pass a strong
refrigerator magnet barely above the rocks and pull out almost all
the bigger magnetite and iron pieces. I place the stuff that that
small magnet collects onto a small paper plate and examine them for
possible suspect stones before tossing them. (kind of like gold
panning, you don't want to throw out a nugget) Then I will drain and
let all the stones in the gold pan dry completely. Once dry, I once
again do the blueberry bounce technique and look over the material
closely again using my low-power m-scope. A hand lens, field
microscope, or illuminated magnifier all work but the low-power
microscope has been the easiest on my vision when used for any length
of time. I also spend time closely examining the rest of the
material in the pan because stonys don't always move with the heavier
materials. Once I find a suspect stone, I pull it out of the pan
with plastic tweezers and place it on a small magnet and put it under
my scope for a good look. Some I recognize to be unique and put them
in vials for study later on, and some I keep for examples of good
meteorwrongs. Usually 99.999% are simply earth rocks, although even
some of those are quite interesting.

Not all the suspect stones are small but most I have found are 1/2"
or less. A waste of time you say? Well possibly, but it has been a
good way for me to learn about meteorites. This hobby has helped me
also get interested in learning about other solar bodies as well as
the earth. I have a lot of folks on the Met-List to thank for most
of that type information. As far as meteorites go, I'm not so much
into buying, selling and collecting. I just really enjoy finding
them myself and seeing them up close.

So again, I hope some of you who live in the "not the best place to
hunt meteorites" give this a try. But be extremely careful how you
handle strong magnets. I wouldn't want to see anyone smash a finger
doing this. If you are one of the young enthusiasts in this hobby, I
would have to recommend you don't attempt to add any magnets to the
cane. Use it just like it comes from the store. I did for a while
and still I found some very interesting stones with it.

I have a picture here that shows both my cane and my latest attempt
at a magnet rake. The rake has three 80 mm square x 10 mm thick NDIB
supermagnets on it. If you look at it and wonder why I spaced the
magnets so far apart on this apparatus, suffice it to say I was too
chicken to get them any closer. I may move the two outside ones in
about an inch each at some point. I can tell you, I had a enough fun
trying to separate them when getting ready to put them on this rake.
I wouldn't want to get a body part in between two of them.

Everything was muddy when I last used both these things. It's cold
and freezing here still so I haven't tried washing them off. I
apologize, the picture is not the best. I think if you can zoom in
on the cane by the wheel of the air compressor, you can still make
out the 2 - 2" magnets there side by side on the front edge. Don't
look too close at the rake, its my first attempt.

I must explain too that my hunting method and the use of water are
not highly recommended by others in the world of meteorites. The
magnetism might affect testing the stone later on, and tap water may
cause rust prone stones to rust.

Anyway, best of luck with your hunting, If you find something, share
a picture or two

Mike in CO

BTW, the last four pictures are of my first finds using my home-made
magnet rake. I have used it twice now on some short distance walks.
I believe the "suspect" iron is a match to 5 other pieces I had
previously found with the cane. Most likely a piece separated out of
an octahedrite, as I suspect the others like it that I have are. I
can't wait for warmer weather so I can take it out to more areas.
Pictures of the stones aren't too good as they are taken with a
camera on the m-scope.

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Received on Thu 21 Feb 2008 03:17:44 PM PST