Hi,
I would add that XRD can be carried out on very small samples but it
requires the use of iron or cobalt radiation and a small diameter powder
camera (50 mm). Both of which in this hi-tech world are hard to locate.
Sincerely,
Ed Sharp
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On Tue, 2 Jan 2007, David Scott wrote:
> Re the Akaganeite [sorry no accent over e in this system]
> problem....first of all I would say that identification by PLM might
> not be sufficient or easy....better to use XRD I would
> say....akaganeite is isostructural with hollandite which can have a
> tetragonal or monoclinic unit cell. Bernal [once thought to be the
> forth man in the famous spy scandal] thought it was tetragonal but
> recent work has shown it is more often monoclinic. Akaganeite has two
> basic morphologies according to Cornell and Schwertmann (2003: 75)
> somatoids and rods. Crystal lengths rarely greater than 0.5 microns.
> Crystals grown at room temperature may be square while those at higher
> temperatures are circular..HRTEM showed that crystals are homogeneous
> ...somatoids are often twinned to give star-shaped or x-shaped ...also
> possible confusion with schwertmannite in absence of XRD data...PLM
> data not specified anywhere as far as I can see. Probable confusion
> with other iron oxides possible in light microscope work. best wishes
> to all for 2007.....David A. Scott
>
> Quoting Donald B Wagner <[log in to unmask]>:
>
> > At 12:19 -0700 1/1/07, [log in to unmask] wrote:
> >> I was hoping that Vagn Buchwald might respond, since he has
> >> published on this
> >> mineral. The email address that I found for him on the web doesn't work - do
> >> you have a current one?
> >
> > Vagn refuses to have anything to do with the Internet - Write to him at
> > this address:
> >
> > Ingeborgvej 4
> > DK-2920 Charlottenlund
> > Denmark
> >
> > Regards
> > Don
> >
> > --
> > --------------------------------------------------------------------------------
> > dr.phil. Donald B. Wagner
> > Jernbanegade 9B
> > DK-3600 Frederikssund
> > Denmark
> > Tel. +45-3331 2581
> > http://alum.mit.edu/www/dwag
> > --------------------------------------------------------------------------------
>
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