ISOGEOCHEM Archives

Stable Isotope Geochemistry

ISOGEOCHEM@LIST.UVM.EDU

Options: Use Forum View

Use Monospaced Font
Show Text Part by Default
Condense Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Mime-Version:
1.0
Content-Type:
text/plain; charset="us-ascii"
TO:
Date:
Tue, 2 Apr 1996 16:31:44 -0500
Subject:
From:
Paul Knauth <[log in to unmask]>
Received:
from ASUVM.INRE.ASU.EDU (asuvm.INRE.ASU.EDU [129.219.13.84]) by elk.uvm.edu (8.7.3/8.7.3) with SMTP id QAA26314 for <[log in to unmask]>; Tue, 2 Apr 1996 16:31:44 -0500 from knauth.la.asu.edu by ASUVM.INRE.ASU.EDU (IBM VM SMTP V2R3) with TCP; Tue, 02 Apr 96 14:31:15 MST
X-Sender:
X-Mailer:
Windows Eudora Pro Version 2.1.2
Message-Id:
Parts/Attachments:
text/plain (29 lines)
At 12:38 PM 3/24/96 +0000, Kolodny wroe:
:
 "...but an opal is an opal"

   Agreed, but there is the question of surface area.  Diatomite has one of
the highest surface areas of anything known.  Most of the OH and water is
probably on the surfaces and can be removed via the stepwise fluorination
method without affecting the tetrahedral oxygen very much..  In the case of
milky opal or precious opal the surface area is nothing special.  Here, the
hydrous components are buried within the structure and it is not clear how
effective the method is. 

  One thing to remember in using the stepwise fluorination method is to NOT
substitute bromine pentafluoride for fluorine gas.  Flourine appears to
yield the right delta-value on quartz or opal as long as you get more than
about 5% yield (a miracle!).  With bromine pentafluoride, a 95% or better
yield is required or your number can be several per mil off.   Cheers,


Paul Knauth
Department of Geology
Arizona State University
Box 871404
Tempe, Arizona 85287-1404
(602) 965-2867 office
(602) 831-1469 home
(602) 965-8102 fax


ATOM RSS1 RSS2