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Re: How to do this? Chondrule separation from matrix.



You can use a dental tool to clean away some of the matrix around
the chondrule that you want to extract trying to avoid the chondrule
surface as much a possible.  But with proper application of the 
tool pressure you should be alble to clean away most of the surface
while the chondrule is in situ.  Then when it is say 3/4th excavated
a small bit of point pressure near its edge should cause it to pop
out.

There is one meteorite, an H-3 that fell in Finland in 1899, Bjurbole?
that has big chondrules that actually fall out of the matrix.  The
meteorite is so fragile that they simply roll out as you handle it.

I have two pieces that I got when I was in college (many, many years ago)
and I had to wrap them in a tight seran wrap to keep them from 
shedding their chondrules.

I was very interested in doing a paper on chondrule surfaces 
using an electron microscope, and this Fin. meteorite was a good
source.

Anyway, once the chondrule is out, a soak in distilled water, then
a brush with a dull wooden matchstick will usually clean them up.


Hope my suggestion helps.


Steve Schoner


>
>I have a number of meteorite specimens that have a fragmented
>area on a broken surface that exhibit extruded chondrules -
>that is, there are roundish chondrules just begging to be unleashed.
>
>Such specimens are Allende and other petrological type 3 and 4
>meteorites.
>
>What I would like to do is extract a single chondrule (about
>1 mm in size or thereabouts) from the matrix of a few meteorite 
>specimens and make a small selection of various chondrule types.
>
>I don't want to disturb the matrix very much, but a small hole is
>acceptable - it's on the back side of an endslice, usually,
>in a broken area not showing fusion crust. I don't want to scratch
>the chondrule if I can.
>
>I'd like to have 5 or 6 little chondrules in a small 'box' with
>labels showing the source.
>
>Has anyone tried this? What happened? What should and shouldn't I do?
>If I did this, what's a good way to display these small objects -
>obviously I will observe them mostly though a microscope. If I use a 
>slide to store them, how can I attach them - Canadian Balsam,
>put them on a clean blank slide and spray them with acrylic to glue 
>them? How do I keep from blowing them away if I spray them? ETC., etc.
>
>I'd appreciate advice from someone who did this or who has some ideas
>on an approach.
>
>Some possible sources would be Allende, Saratov, Jilin, etc.
>
>Trying to get a small microprobe is difficult - in biology, one usually
>fires the center of a glass rod to melt it, makes a quick pull, and then observes
>what results. Doing this several times eventually results in a nice
>very sharp point on a microscopic scale - by comparison a common pin
>is a crowbar.
>
>I can do this - but I don't think glass will be strong enough to pry 
>a chondrule.
>
>Maybe I can drill or sand a dental probe to a microscopic point? I tried
>a Dremel tool on some tips with no success - still the points are very 
>gross on the sub-millimter scale. Maybe I need a special bit to sand
>these - or just sand by hand on 1200 grit silicon carbide?
>
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