[meteorite-list] do meteorites fluoresce??

From: Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Wed, 28 Feb 2007 20:33:38 -0500
Message-ID: <016901c75ba1$a34f3d50$6402a8c0_at_Dell>

Thanks to all who asked and contributed to this very interesting question,
Barb for asking Tom for answering.
Jeff, thanks especially for the information and link.
Elton thank you also for contributing. All helped to put this into
perspective.
An extrodinary phenomenon, what?
Jerry Flaherty
----- Original Message -----
From: "Jeff Grossman" <jgrossman at usgs.gov>
To: <meteorite-list at meteoritecentral.com>
Sent: Wednesday, February 28, 2007 8:21 PM
Subject: Re: [meteorite-list] do meteorites fluoresce??


> At 05:49 PM 2/28/2007, Mr EMan wrote:
>>In the "for what its worth" category, the degree of
>>fluorescence in feldspar chondrules is the means for
>>defining the intermediate grades within the 3 grades,(
>>e.g 3.1, 3.2 , etc.) I don't know what wavelength is
>>the standard for that examination. If you've the
>>fluorscent microscope and knowing those standards you
>>might be able to observe this in common chondrite thin
>>sections but I think it would be in some form we
>>wouldn't easily recognize. A coverslip would of course
>>block UV, but uncovered slides attract lint which
>>glows brightly.
>
> Actually, the property that is used to determine the petrologic types
> of chondrites is thermoluminescence (TL), not fluorescence. TL is
> the emission of light in response to heating a sample, and it is a
> very small effect. The fluorescence you are talking about is the
> emission of light after absorption of light of a different wavelength
> (often UV).
>
> In point of fact, many meteorites do show a spectacular variety of
> luminescence, namely cathodoluminescence (CL). This is emission of
> light in response to bombardment with an electron beam, as in
> CRTs. Type 3 ordinary chondrites are particularly beautiful, with
> different minerals glowing red, blue, and yellow. Check out the work
> of Derek Sears at:
> http://www.uark.edu/depts/cosmo/research%20projects/CL%20mosaics/
> There are small, portable instruments that can be used to look at CL,
> but probably they won't be found outside of labs.
>
> jeff
>
>
> Dr. Jeffrey N. Grossman phone: (703) 648-6184
> US Geological Survey fax: (703) 648-6383
> 954 National Center
> Reston, VA 20192, USA
>
>
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Received on Wed 28 Feb 2007 08:33:38 PM PST