[meteorite-list] Re: rust and crust
From: Stephen McMann <stephen_mcmann_at_meteoritecentral.com>
Date: Thu Apr 22 10:16:35 2004 Message-ID: <Law9-F1073bHlwWkVNq00074ee6_at_hotmail.com> <html><div style='background-color:'><DIV> <P>Dear List,</P> <P>I thought that I would ask a question relating to the never-ending rust thread. I hope that this has not already been fully addressed. As a fairly new collector I may not be familiar enough with the archieves. Those who are tired of rust discussions should not read this.</P> <P>A large part of my collection consists of Sikhote individuals. Of course one of the many things that makes Sikhotes appealing is that they are usually relatively stable. This combined with their abundence makes it tempting to treat them carelessly. However, I wish to err on the side of caution. I want mine to be in good condition many years from now.</P> <P>I have taken measures to inhibit the arrival of fresh Cl- and moisture. They currently live in plexiglass cubes with VCI paper and silica dessicant. Several were wiped with a silicone gun cloth. However, I aquired my SAs from a variety of sources and can say little about their histories. I am sure that at least some of them have been held in sweaty hands. One of them (a fairly well oriented individual) is shedding flakes, suggesting that it is sick.</P> <P>Of course another characteristic of SAs is that individuals are covered with a delicate crust whose characteristics have been determined by some combination of rapid passage through the atmosphere, post-fall weathering in the field, and post-collection treatment. Some crusts are black, rich in magnetite, and often smooth or marked with flow lines. Other crusts are more orange, rich in limonite, and can be avariety of textures. I'll say that both kinds of crusts can be interesting and attractive. On the other hand I don't want a meteorite with a touch of orange to turn into a ball of poo.</P> <P>I have been intrigued by recent discussions about stabilization treatments such as soaking meteorites in alcohol and perhaps adding some NaOH to help remove CL-.</P> <P>Now the question.</P> <P>Can anyone tell me what treatments are best for stabilizing crusted meteorites? In particular, how will NaOH affect the various kinds of crusts that you can find on SAs?</P> <P>Thank You</P> <P>Stephen McMann</P> <P><BR><BR> </P><FONT face=3Darial,helvetica><FONT face=3Darial,helvetica></DIV></FONT></FONT></div><br clear=all><hr> <a href="http://g.msn.com/8HMGENUS/2728??PS="><b>MSN 8:</b> Get 6 months for $9.95/month.</a> </html> Received on Thu 21 Aug 2003 01:16:22 PM PDT |
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