[meteorite-list] RE: Crust and Meteorite Thin Sections

From: Jeff Pringle <jpringle_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:15 2004
Message-ID: <60D827D3A75FD7119B15006008A820BB0EC79A_at_DEAN1>

To Mark and list -

Thanks for the reply and the cool photos!
I realize the actual structure of the rock is what counts, I just happened
to find a meteorite (OC) last year due to it's crust, and am now fixated on
crusts as a way to differentiate earth from space rocks.
I'll get over it eventually.
I was hoping for a shortcut that involves a less intense level of optical
mineralogy knowledge. Isotropy can be determined with a regular microscope,
two polarizers and some duct tape, but seeing how much anorthite is in yer
plagioclase or separating the various clinopyroxenes is more challenging and
is perhaps impossible without real knowledge and equipment. I've got a copy
of Nesse and am learning as fast as I can, but would still like to be 95%
sure a rock is extra-terrestrial before I bother a planetary scientist with
it for classification. It is the achondrites that are harder to get to that
level of sureness. And if I pick up an unusual rock, I want to know if it's
a meteorite NOW. (Of course, it's easy - the answer is NO!)
But it looks like there are no shortcuts, I will keep hitting the books and
the Ansmet petrographic descriptions, and spend my tax refund on a real
microscope.
Thanks for your help!
Jeff
Received on Mon 19 Apr 2004 02:06:04 PM PDT