[meteorite-list] R Chondrites and Magnetism

From: Tom Knudson <peregrineflier_at_meteoritecentral.com>
Date: Tue May 31 13:18:17 2005
Message-ID: <005c01c56604$bb9c9270$2d107918_at_Michelle>

Hello List, this has been very educational and I would like to thank
everyone! So, most R's have enough metal to be attracted to a powerful
enough magnet, while a couple have quite a bit of iron, my question has been
answered
  If I had a big enough collection, I would not have to ask the list for
help, I would just check my self, so I am sure glad you all helped!
  Now, I have to go back and read through all of these emails and websites
to see if I can find out why R's have so little metal.

Thanks, Tom
peregrineflier <><

----- Original Message -----
From: <bernd.pauli_at_paulinet.de>
To: <Meteorite-list_at_meteoritecentral.com>
Sent: Tuesday, May 31, 2005 7:09 AM
Subject: [meteorite-list] R Chondrites and Magnetism


> Hi Tom and List,
>
> Here is an excerpt from the "good old" RFS:
>
> NORTON O.R. (1998) Rocks From Space, pp. 190-191:
>
> and iron-nickel metal is nearly absent. Most of the metal is in the
sulfides
> pyrrhotite (FeS) and pentlandite [(Fe,Ni9)S8] or combined with olivine.
The
> pyrrhotite is magnetic, giving the meteorites a *w e a k m a g n e t i c
> a t t r a c t i o n*. The fayalite content averages about Fa39, which is
the
> highest iron-bearing olivine content of any of the chondrites and is
chemically
> the most distinctive characteristic. Rumurutiites have the highest iron
oxidation
> of the chondrite class.
>
> see also:
>
> BLAND P. et al. (1992a) A unique type 4 chondrite from the
> Sahara - Acfer 217 (abs. Meteoritics 27, 1992, 204-205):
>
> "Acfer 217 is a chondrite that is exceptionally poor in metal and
> sulfide and rich in oxidised Fe. It appears to be unique ..."
>
> and also:
>
> SCHULZE H. et al. (1994) Mineralogy and chemistry of Rumuruti:
> The first meteorite fall of the new R chondrite group
> (Meteoritics 29-2, 1994, pp. 275-286):
>
> "Meteorites of this new group can be characterized as
> oxidized, olivine-rich, metal-poor chondrites, ..."
>
> And, as Buckleboo Martin wrote: No metal or hardly any metal
> automatically implies no magnetism or extremely weak magnetism.
>
>
> Best wishes,
>
> Bernd
>
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Received on Tue 31 May 2005 01:18:15 PM PDT