[meteorite-list] Blue Bits in NWA 1584 Chondrules

From: tett <tett_at_meteoritecentral.com>
Date: Sat Jan 29 11:48:06 2005
Message-ID: <002501c50622$4fd08ed0$6400a8c0_at_Tettenborn>

Bernd and Darren and List,

I too have a wonderful end cut of NWA1584 purchased from Dean a while back.
I believe Dean was the original dealer of this material. From my end cut I
also had a wonderful TS made.

This is a very beautiful and fresh meteorite showing large chondrules and
clasts and many troilite inclusions in a milky white/grey matrix. My end
cut also has a beautiful black and very thin fusion crust with polygonal
contraction cracks.

Alas, my specimen does not have any of the unique bluish inclusions that
either of you have found. Both at 20x and 40x I could not find any hint of
these.

Congratulations!

tett
----- Original Message -----
From: <bernd.pauli_at_paulinet.de>
To: <Meteorite-list_at_meteoritecentral.com>
Sent: Saturday, January 29, 2005 8:14 AM
Subject: [meteorite-list] Blue Bits in NWA 1584 Chondrules


> Hello Darren and List,
>
>> I was scanning some NWA 1584 slices (one of my favorite
>> meteorites) and I noticed some iridescent-looking blue
>> areas in some of the chondrules on one of them. I looked
>> at the areas with a 20x hand lens and the blue is really
>> there, ... anyone know what is causing this effect? The
>> chondrules (if those are indeed chondrules) are around a
>> centimeter across.
>
> http://webpages.charter.net/garrison6328/bluebits1.jpg
> http://webpages.charter.net/garrison6328/bluebits2.jpg
>
> Yes, NWA 1584 is a beautiful, fresh LL5 chondrite -- this is
> true at least for the specimens the Hupes offered some time ago.
> Some other specimens that are being offered on EBay right now
> look more severely weathered.
>
> I have a very nice 10.8-gram crusted endcut from the Hupes and, here
> is what it looks like: It has a grayish matrix with several clasts and
> chondrules.
>
> There is about 60% fresh black fusion crust showing polygonal contraction
> cracks. A major feature is several large, mostly globular troilite
> aggregates
> (up to 5 mm in longest dimension).
>
> I looked for those ominous, bluish areas and I found some at high
> magnification
> (32x and 56x), although they are not as conspicuous as yours. To me they
> have
> a bluish/violet iridescent appearance and when I slowly rotate my specimen
> under
> the microscope this iridescence appears and disappears periodically.
>
> So it seems that this is (at least in my specimen) light reflected off
> mineral grains (troilite, and, well, maybe chromite or ilmenite).
>
> Darren, I'm going to attach three NWA 1584 JPEGs in separate mails to you
> so that you see what I am talking about. One of these JPEGs shows a 5 mm
> troilite inclusion (magnification 32x), #2 shows four of these violet/blue
> things (magnification 32x) and another is a wide-angle pic of my specimen
> (also showing this conspicuous 5 mm troilite inclusion at the upper left).
>
>
> Best wishes,
>
> Bernd
>
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Received on Sat 29 Jan 2005 11:48:07 AM PST