[meteorite-list] "golden iron color" of Aziz Habibi's new iron

From: bernd.pauli at paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: 01 Apr 2010 22:25:10 UT
Message-ID: <DIIE.000000A70000483B_at_paulinet.de>

Hello Aziz and Forum,

http://www.flickr.com/photos/azizhabibi/page3/

Aziz asked: "what is the process that make it looking like that"

Me too, I recall having seen that before but don't remember
exactly where, when and what ... Willamette maybe ???

I can offer three [theoretical (!)] solutions to this gold coloration:

1) the result of an etching process in situ
2) an *extremely* phosphide-rich iron
3) a combination of (1) and (2)

(1) and (3) might explain Aziz's question about "why the Widmanst?tten
pattern is showing on the surface". => a result of etching (in situ)

(2) is a promising theory too because schreibersite is yellow in reflected
light. To me it looks slightly brownish and Buchwald says that "compared
to cohenite, [schreibersite] is distinctly more brownish."

Buchwald also says that "when the phosphides happen to be located in the
heat-affected alpha2 rim zone,...they will melt when rapidly reheated above
1100?C.

Just a thought, no more, no less,

Bernd
Received on Thu 01 Apr 2010 06:25:10 PM PDT