[meteorite-list] Re: Tumblin' Stoney Space Rocks
From: E.L.Jones <jonee_at_meteoritecentral.com>
Date: Thu Apr 22 09:42:05 2004
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<p>Interesting idea and if they did tumble successfully , due to differential
grinding, you might have a surface which resembled toad skin. Common
chondrite meteorites may appear "hard" but they lack interlocking crystal
structures which make other stones polish up in the tumbler. Meteorites
are non-homogeneous rocks. You might be able to tumble them one at a time
and not have them break. (Anyone have some meteorites they
are willing to bang together for a few hours to see what is left?...Didn't
think so.) Since it is not my meteorite being tested....I'd like
to know what turns out. We have had this discussion before and the
consensus then was that it was undoable.
<p> The hardness scale used in mineralogy doesn't apply to a meteorite
<i>per se</i>. . We hear that "olivine" has a hardness of 6 but I
can scratch some meteorites with fluorite at a hardness of 4.
It tends to make crumbs/flakes and not a "scratch" in the sense of mineral
identification. Fluorite will tumble and turns out some good pebbles but
it is a mineral , is interlocked, and is homogeneous. The components of
a meteorite are of varying hardness. AS such they tend to under grind
and over grind and you don't get a close average. A water slurry,
of course, would rust away your metal and you'd never get rid of lawrencite.
<p>Unless you are after meteorite crumbs/dust and metal filing sized flecks
of rustable iron nickel, you are going to polish them by hand. I have seen
some meteorites with a dark ebony matrix which polished up very nicely
but nothing mirror smooth.
<p>Some people have tumbled iron shale and gotten the remaining metal kernels
out of the shale.
<blockquote TYPE=CITE>I have a friend who is a jeweler and artisan. He
saw how relatively
<br>inexpensive the material is and asked me whether it can be tumbled
in a rock
<br>tumbler and polished.
<p>I showed him pics of a Sahara 00173 Meteorite Slice I have in transit
<br>and noticed its grainy look to it.
<p>He also noticed that some of this material is referred to as uglies
<br>they were less than desirable for collecting.
<p>I told him my feeling is that to survive the heat and violence of passing
<br>thru the atmosphere, even the stony meteorites would be incredibly
<br>probably take months to tumble.</blockquote>
Received on Thu 25 Jan 2001 02:48:04 AM PST