[meteorite-list] What would a meteorite look like if found in water?

From: Adam Hupe <adamhupe_at_meteoritecentral.com>
Date: Thu Apr 22 10:27:53 2004
Message-ID: <03de01c3b45a$16c3e8a0$d2dbe60c_at_attbi.com>

Dear Maria and List Members,

I was asked what a meteorite might look like if it was pulled from a body of
fresh water because this is where Maria chooses to search. I find this
question interesting because I have hunted for meteorites in shallow water
before. I do not have many good references so perhaps another list member
could add something to this string.

My inadequate response:
I am a amateur treasure hunter who likes to hunt old swimming holes in
shallow water (less than 20 feet) and have pulled out all kinds of metal
objects. They weather differently depending on which body of water they
were pulled from. I have seen brass turn red and fall apart in your hands
because of electrolytic effects introduced by vegetation decaying into a
lake. Old silver coins and jewelry usually come up encrusted in a black
silver oxide coating. Iron comes up severely crusted in brown oxides many
times thicker than the original object. Old nickels turn red and it is hard
to make out features like dates. Gold is the only thing that is not
affected. The reason I mention all of the above objects is to demonstrate
how quickly items deteriorate under water. All of the above listed items
were in water less than a hundred years and are already showing heavy signs
of deterioration. It is doubtful that an iron meteorite would last very
long even in fresh water. Another problem would be when it was removed from
its resting place and introduced to air. I believe most would crumble like
a bad Nantan days after being exposed.

Using a magnetic sluice in shallow fresh water I pulled out hundreds of
magnetic stones only one of which was a meteorite. It only weighed 1.5
grams and had a silver-gray looking crust like the semi-metallic sheen on
magnetite. I ground a small corner and did not see any metal. I could
barely see the outlines of a few round structures in a dark orange matrix
indicating to me some kind of chondrite. Surprisingly this tiny meteorite
was not friable at all. I believe the way it weathered under water actually
helped preserve the integrity of the matrix. The portions that oxidized
actually acted like a glue holding the rest together. I was told at first
it was not a meteorite but insisted that I thought it was and eventually it
was proven to be under a Microprobe two years later. At that time it was
assumed to be a paleo meteorite brought in on a glacier that scoured out the
lake. Since the chain of custody was interrupted I cannot prove without a
doubt this was Washington States sixth meteorite which means I will be
looking for another specimen.

The problem is that I cannot prove I pulled this stone from the water
because the chain of custody was interrupted even though my hunting partner
and myself clearly remember pulling it from the lake in the sluice.
Scientist can not rely on peoples memories which have been proven time and
time again to be inaccurate so if you do find something be sure to mark it
clearly and keep it away from the rest of your collection. The reason I say
keep it away from the rest of your collection is because it would be easy
for a small meteorite to fall out of a bag, be picked up while looking at
your suspected material and introduced into your find pile. I would never
claim something as important as a new meteorite find without documentation
from the start proving how important it is not to rely on your memory.

All the best,

Adam Hupe
Received on Wed 26 Nov 2003 03:15:47 PM PST