[meteorite-list] Meteorite Cleaning

From: Mike Groetz <mgroetz_at_meteoritecentral.com>
Date: Thu Apr 22 09:42:00 2004
Message-ID: <3A6119FD.347B0B3E_at_greenapple.com>

Hello-
   I am new to the hobby of meteorite collecting and am very excited
about it. Even though by no means am I familiar with chemistry, I made a
discovery that I am very pleased with and wanted to share with you-
   Recently I purchased a DHOFAR H4/5 meteorite weighing about 36 grams.
The photo I purchased from showed a small amount of white "caliche"
(calcium carbonate) on the corners of the meteorite. This is supposed to
be frequently found on meteorites from desert climates. I have to admit
that when I received it I was a little disappointed in that the white
was all over the backside not seen in the photo.
   From what I have read, this can be removed with a fairly strong
sulfuric acid. But I have no idea where to find it.
   OK- don't laugh. While cleaning the bathroom, I was using an over the
counter product called "The Works" that is advertised for removal of
rust stains and hard water build up. I know this stuff is fairly strong
(it contains phosphoric acid) and all at once I wondered what it would
do to the caliche on my meteorite.
   So I got up the courage and put the meteorite in a small cup and
covered it with the cleaner. Immediately the white caliche started
bubbling and boiling away from the meteorite. After a few minutes, it
seemed to slow, so I took an old toothbrush and lightly scrubbed the
meteorite and put it back in the cleaner. Again, the white caliche was
bubbling away and I could see fine particles of the caliche coming off.
   After about 30 minutes and a few gentle scrubbings, the meteorite was
totally clean of the white. I rinsed it in water and lightly paper
toweled it dry. Then to insure total drying, I sprayed it with Albany
brake parts cleaner (a combination of Heptane and Toluene) that is
advertised to "clean and dry quickly with no residue". Within seconds,
the meteorite was dry and really looked great and natural. This was now
the meteorite I wanted.
   The cleaning did not change any of the original light brown
coloration or the partial blackened crust. It is free of the caliche.
   I know this was not professional, but for me, I am really pleased and
wanted to share it with all of you.

Mike
Received on Sat 13 Jan 2001 10:16:14 PM PST