[meteorite-list] Are_Mars_Meteorites_Magnetic?

[Linton Rohr]

Thank you Zelimer (and Pete) for the additional information on this subject,
and also for the words of wisdom in your closing...

"(In French we use to say "Bonne Année", meaning "Good New Year". But I
prefer by far the English wording. ***Indeed, it is not beacuse the year
is good that you'll necessarily be happy. It mostly depends on your
mental spirit and your intrinsic optimism. Some may be poor and/or ill
but still very happy.***
I therefore wish everybody to acquire a very positive mantal spirit in
any circimstance, so far for this unpredictable 2012...)"

I'll second that! HAPPY New Year to all!
Linton

----- Original Message ----- 
From: "Prof. Zelimir Gabelica Université de Haute AlsaceENSCMu," 
<Zelimir.Gabelica at uha.fr>
To: <meteorite-list at meteoritecentral.com>
Sent: Friday, January 06, 2012 2:07 AM
Subject: Re: [meteorite-list] Are_Mars_Meteorites_Magnetic?


> Hi Pete,
>
> Your statement that magnetite (Fe3O4) is one part wüstite (FeO) and  one 
> part hematite (Fe2O3) is formally true (in terms of formula  adjustment) 
> but not totally, regarding its physico-chemical properties  and especially 
> its structure, that are different from what would  result in a mechanical 
> admixture of wüstite and hematite.
>
> Magnetite is actually a Fe(II) ferrate(III).
>
> It should be written more correctly as Fe(Fe2O4) where the first iron  is 
> a bivelent cation Fe(II) or Fe2+ that neutralizes an anion which is 
> (Fe2O4)2- and in which the 2 irons are Fe(III) or Fe3+
>
> As Fe(II) is more electropositive than Fe(III), it preferably acts as 
> cation while Fe(III) ions would more readily be surrounded by enough 
> oxygens so as to build up an anion.
>
> This being, I did not check whether the permeability of magnetite  results 
> from that of wüstite or whether it is rather rearranged  otherwise, which 
> should be far more likely in reagrd with the  completely different 
> magnetite structural rearrangement.
>
> Thanks you (and Greg) for your clear discrimination between  "magnetism" 
> and "permeability", that really needed to be reminded.
>
> More precisely, in electromagnetism, permeability is the measure of  the 
> ability of a material to support the formation of a magnetic field  within 
> itself. In other words, it is the degree of magnetization that  a material 
> obtains in response to an applied magnetic field (info from  Wikipedia).
>
> Happy New Year to all!
>
> (In French we use to say "Bonne Année", meaning "Good New Year". But I 
> prefer by far the English wording. Indeed, it is not beacuse the year  is 
> good that you'll necessarily be happy. It mostly depends on your  mental 
> spirit and your intrinsic optimism. Some may be poor and/or ill  but still 
> very happy.
> I therefore wish everybody to acquire a very positive mantal spirit in 
> any circimstance, so far for this unpredictable 2012...)
>
> Zelimir
> -- 
> Prof. Zelimir Gabelica
> Université de Haute Alsace
> ENSCMu, Lab. LPI-GSEC,
> 3, Rue A. Werner,
> F-68093 Mulhouse Cedex, France
> Tel: +33 (0)3 89 33 68 94
>