Tom, The problem/solution is discussed in the following e-mails by Mike Groetz and Donald O'Keeffe:
[meteorite-list] Meteorite Cleaning Mike Groetz [EMAIL PROTECTED] Sat, 13 Jan 2001 22:16:14 -0500 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 [meteorite-list] Meteorite Cleaning Donald O'Keeffe [EMAIL PROTECTED] Sun, 14 Jan 2001 17:47:24 -0600 Hi Mike, I use lime-a-way on my keepers. Removes the caliche and doesn't harm the stone as far as I can tell. I think "The Works" is what the kids in my neighborhood use for bombs. I'm not exactly sure how they do it, shredded aluminum foil I think. Sure does rattle the windows on the Fourth of July. Don End Quote Hope this helps.... Best, Ken Newton http://home.earthlink.net/~magellon/mepage.html Meteor-Wrong Central Tom aka james Knudson wrote: > Hello List, The gold basin I found yesterday that was buried has a some kind > of white deposit forming on it. What is this, and haw can I remove it > safely? > > Thanks, Tom > The proudest member of the I.M.C.A. #6168 ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
