[meteorite-list] Cleaning a heavy iron meteorite

From: Graham Ensor <graham.ensor_at_meteoritecentral.com>
Date: Fri, 11 Nov 2011 23:11:38 +0000
Message-ID: <CAJkn+kaE0KY6ptoHUSbEpO2iAi=46BMH+cDRtbymcos0yA27sQ_at_mail.gmail.com>

Hi again,

I would be very wary of using wire brushes to clean a meteorite that
has an obvious black fusion crust hidden underneath. I have a 12kg
xxxNWA that was covered in white caliche which I cleaned chemically,
painstakingly bit by bit, neutralizing the acid every cm or so to stop
any soaking into the matrix and then washing in distilled water and
baked for a long time....it has remained very stable for many years
now.
It revealed delicate flow lines, regmaglypts, rollover lips and frothy
black bubbling perfectly preserved....I was amazed at what was
uncovered. All that would have been lost with a wire brush and
vigorous mechanical cleaning. It is to note however that some caliche
is very resistant, even to acid, and I was perhaps lucky with this
particular one. Also it would be very unwise to try this on any rare
types.

A wire brush may be ok on an old very weathered chondrite but even
with mechanical cleaning it should be done carefully, in the manner
that fossil preparation is undertaken if there is any special detail
that you want to reveal under caliche or other terrestrial covering.

Good luck,

Regards,

Graham

On Fri, Nov 11, 2011 at 9:20 PM, Count Deiro <countdeiro at earthlink.net> wrote:
> Hi Abe,
>
> You were correct in finally using a soft "stainless" steel brush. The greyish brown color is probably as close as your going to get after laying a little "gold" on the rock. If your just wanting to make it look nice and not going to study it, I ?would immerse this stone meteorite in 90% alcohol for ten minutes and then bake it dry at 325 degrees for about ten minutes. Polish it off with a micro-fiber cloth.
>
> A greyish brown, with patches of darker fusion crust, in a weathered chondrite is pretty close to normal. Especially after it has terrestialized to the point of the partial, or complete, dissapearance of visible fusion crust. Although meteorites can sure vary according to their origin, cosmic and terrestial life.
>
> If you keep the recent "Meteorite of the Day" pics of a couple of days ago, look at my Stump Spring LL6 weathered chondrite which was treated as described above. Washed with distilled water. Dryed. Stainless dremel to remove terrestial caliche, etc. and then alcohol soak and drying. Then polished with micro-fiber cloth.
>
> Good luck,
>
> Guido
>
>
>
>
> -----Original Message-----
>>From: Guenther <abe.guenther at mnsi.net>
>>Sent: Nov 11, 2011 8:11 AM
>>To: meteorite-list at meteoritecentral.com
>>Subject: [meteorite-list] Cleaning a heavy iron meteorite
>>
>>Hi all,
>>
>>A year ago I found a large heavy iron meteorite. When I found it the color
>>was a dark brown. In my attempt to bring out the true color, I decided to
>>use a dremel tool with a fine wire brush bit to clean it. The dremel brush I
>>used was extremely soft and gold in color and it turned slightly gold in
>>color. So, I bought a soft stainless steel wire brush and now it turns grey
>>when I brush it. What is the best way for me to clean it to get the true
>>color?
>>
>>Here are the original images after I used the gold color brush:
>>
>>http://aguenthe.mnsi.net/NM1.jpg http://aguenthe.mnsi.net/NM2.jpg
>>http://aguenthe.mnsi.net/NM3.jpg http://aguenthe.mnsi.net/NM4.jpg
>>
>>Thanks,
>>
>>Abe Guenther
>>
>>
>>
>>______________________________________________
>>Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html
>>Meteorite-list mailing list
>>Meteorite-list at meteoritecentral.com
>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>
> ______________________________________________
> Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
Received on Fri 11 Nov 2011 06:11:38 PM PST