[meteorite-list] Re: petrological grade....(H3.0--H3.9)

From: entropydave <entropydave_at_meteoritecentral.com>
Date: Thu Apr 22 09:46:25 2004
Message-ID: <009901c0e495$2f1c0780$18a689d4_at_default>

Hi frank,
Thanks a lot for that - that was actually very good info - I have only small
knowledge of geology and the aspect of the feldspar's luminescence was news
to me too!
thanks!
dave
----- Original Message -----
From: E.L. Jones <jonee_at_epix.net>
To: entropydave <entropydave_at_ic24.net>
Cc: metlist <meteorite-list_at_meteoritecentral.com>
Sent: Thursday, May 24, 2001 2:17 AM
Subject: Re: petrological grade....(H3.0--H3.9)


> Frank Cressy answered this recently, presented here from his message.
> Elton
>
> Petrographic grades 3.0 through 3.9 are obtained by measuring changes of
> thermoluminescence (TL) of chondrules. TL measures the luminesence of the
> sample after it is irradiated.
>
> During mild metamorphism, tiny grains of feldspar start to grow in a
glassy
> chondrule. The higher the metamorphism, the more feldspar is present and
> feldspar causes a marked increase in thermoluminence. This allows one to
> subdivide the petrographic grade 3 meteorites.
> Hope this helps.
> Regards,
> Frank
>
> entropydave wrote:
>
> > hello,
> > I wonder if someone can explain the decimal pet grades such as H3.4 or
H3.7?
> > yours curiously...
>
Received on Thu 24 May 2001 05:04:21 PM PDT