[meteorite-list] Fe-metal (Ni-free) in diogenites

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:29 2004
Message-ID: <3D8C6524.6922CF23_at_lehrer.uni-karlsruhe.de>

Adam wrote:

> This stone consists of ... troilite, and Fe-metal (Ni-free)

Frank wrote:

> not familiar with any meteorite where the iron portion
> isn't associated with nickel. Are there any others?

Bernd wrote:

> NWA 1109, eucrite: "accessory minerals in clasts and matrix
> ... ilmenite, Ni-free Fe metal, chromite, baddeleyite and apatite."

Hello again,

I just found another NWA with "pure metal" and this time it is
even a diogenite (like the unique olivine diogenite NWA 1459):

NWA 1239, ADIO, polymict breccia

A single stone of 237 g was bought in Zagora in 2001 May. The meteorite
is a polymict breccia that contains more than 90 vol% orthopyroxene
fragments. Classification and mineralogy (J.-A. Barrat, UAng, M. Bohn,
I-CB, V. Sautter, MNHNP, Ph. Gillet, ENSL): typical orthopyoxene
En70-72Wo2 (FeO/MnO molar = 32), but many more ferroan grains exist,
contains inverted pyroxenes of eucritic origin, Fs27 Wo45 to Fs64 Wo2
and Fs22Wo44 to Fs51 Wo1 (two grains), calcic plagioclase An94-An81,
olivine Fa40-Fa55, m e t a l , p u r e Fe and FeNi, and troilite.

Specimens:

Type specimen, 22 g and one polished thin section, ENSL; main mass
is with the anonymous purchaser (Met.Bull. 86, 2002, A163-A164).


Regards,

Bernd
Received on Sat 21 Sep 2002 08:25:08 AM PDT