[meteorite-list] Thin section not so thin...

From: dean bessey <deanbessey_at_meteoritecentral.com>
Date: Sun, 30 Oct 2011 15:05:24 -0700 (PDT)
Message-ID: <1320012324.36347.YahooMailClassic_at_web65911.mail.ac4.yahoo.com>

As a ebay seller of thin sections I thought that I would respond to this. I should point out that it wasnt me that David bought his thin section from, I dont know who he bought them from, dont know anything about his thin section and am in no way commenting on any other seller when I write this.
It should be pointed out that in order to be a "Thin Section" it does not have to be 30 microns. Thin Sections are extensively used by various scientific and commercial organizations for various purposes and in particular mining and petroleum companies make great use of thin sections.
Depending on what you are trying to do different thickness's might be most useful. For meteorite classification purposes it must be 30 microns as the light will be different from what it is supposed to be if it is some other thickness (All of my own thin sections are 30 microns). There are other standard thicknesses and 100 microns I believe is the most common (And possibly cheapest to make). 50 and 200 micron thickness thin sections are also standard thicknesses (But meteorite people rarely would want one this thickness).
We on this list are most familiar with 30 microns because thats the thickness thats needed for meteorite classifications. If you were working as a geologists with a petroleum company you might be more familiar with 100 micron thin sections.
I suspect that the thin section David bought was made to a different standard than for what you usually need for meteorites. It would be odd to be exactly another standard thickness if it was just a poor job. (For example if it was say 85 microns I would probably say that it was a poor job as probably nobody would ever make a thin section that thickness no matter what the planned use was)
I would also like to comment on the price of thin sections. You will notice that my meteorite thin sections are priced cheaper than most other sellers (Started on ebay as low as $29.95). When I left Canada 7 years ago I left a container of stuff in storage which I only got earlier this year. Since it was all paid for more than half a decade ago I am selling off a lot of it with no regard to my cost or replacement value. My thin sections fall in this catagory. I cant replace thin sections and make money at $29.95.
I will not get into a slugging match by saying mine are better than other people and you should pay more for mine because of that but if you do see thin sections cheaper than what I currently have listed I would be suspicion and ask questions before I buy. Its possible that somebody in a country where labour is cheaper can make them cheaper than me (Although I would love to know if anybody does find a place)
Questions that you should ask are:
(1) Thickness. Are they 30 micrions, 100 micron or some other thickness (I am assuming that the seller would know this)
(2) Are they Polished? Unpolished thin setions can easily be made for under $20. It costs as much to polish them as it does to cut them. Both have their uses but polished ones are twice as expensive (And needed if you want to get the meteorite classified).
(3) Do they have a cover slip? If you will carbon coat them and put them in a microprobe (Needed if you buy one of my "Thin scetion kits" on ebay and send it for classification) you DO NOT want a cover slip. If you are just using them with a standard microscope and showing them in schools you might want the cover slip so it wont get scratched.
Hope this helps somebody
Sincerely
DEAN (AMUNRE on ebay)
http://stores.ebay.com/The-AmunRe-Museum/_i.html?_nkw=thin+section&submit=Search&_sid=1598024










--- On Sun, 30/10/11, David Allepuz <dallepuz at telefonica.net> wrote:

> From: David Allepuz <dallepuz at telefonica.net>
> Subject: [meteorite-list] Thin section not so thin...
> To: meteorite-list at meteoritecentral.com
> Received: Sunday, 30 October, 2011, 12:46 PM
>
> Hello list,
>
> A few weeks ago I bought a NWA869 thin section from an eBay
> seller.
>
> The seller is not Mirko Graul (excellent thin section
> seller, excellent person, my favorite? thin section
> provider) nor any known thin section seller of this list, OK
> ?
>
>
> When received it looked darker than usual and after
> measuring thickness it was 100 micrometers instead of 30.
> I just contacted the seller to prevent it from selling more
> thin sections like this and having problems with costumers,
> but in a educational and collaborative way, as I think he
> was new in thin sections and did not know about the
> problem.
> The thin section was really cheap, so I keep it, no
> problem.
>
> Ok, well, my help claim is because I want to grind that
> thin section to 30 micrometers and I think the best way is
> to do it the same way as I did when I grind my telescope
> mirror, using a second glass as a grinding tool.
> Any suggestions?
> Do I use carborundum 2000 or Aluminium Oxide?
>
> Thank you.
>
>
> David Allepuz
> Corbera de Llobregat
> Catalonia -SPAIN
>
> www.meteorits.cat
> www.cazameteoritos.es
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Received on Sun 30 Oct 2011 06:05:24 PM PDT