Why this rock is probably not a meteorite:
I found this photo on eBay. The
seller claimed the item to be a slice of a rare kind of meteorite,
a mesosiderite.
Actually, the words were "unclassified Rare Mesosiderite Stony iron
meteorite." "Unclassified" is a euphemism for "this
rock has not been authenticated as a meteorite by the scientific
community." The seller provides no information to back up his
claim that this rock is a meteorite. The ad mentions that the rock
has "beautifull [sic] chondrules," but I can't see any
in the photo (and, I think that mesosiderites don't contain chondrules,
but I may be wrong).
There's a lot of mumbo-jumbo about
magnetic
susceptibility, which can be a quick and useful property to
test and identify some kinds meteorites (e.g., Rochette
et al., 2007).
A measurement of magnetic
susceptibility may be able to show that a rock contains metal,
but it cannot prove that the metal is an iron-nickel alloy (meteorite)
as
opposed
to just iron (slag).
The rock does not look like a meteorite to me.
It has lots of vesicles. Mesosiderites
don't have vesicles. If the bright spots are iron metal, then they're
not shaped and distributed like
metal in a mesosiderite.
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What is it?
If the bright spots are metal, then it's probably
a piece of slag.
There are many legitimate meteorite dealers who sell real meteorites
on eBay. There are also good people who sell rocks that they think
might be meteorites, but who really don't know anything about meteorites,
so they're probably wrong. Finally,
there are a few nasty people who sell funny-looking rocks that they
know are are not meteorites.
Caveat emptor.
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