[meteorite-list] Tektite Identification

From: Treiman, Allan <Treiman_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:23 2004
Message-ID: <9CBE44BF7DE9D511960300500424D7D0112138_at_cassnt2>

A further question --

  How can you tell one kind of tektite from another?
Say an australite from a bediasite from a small
indochinite?

  Allan

Allan H. Treiman
Lunar and Planetary Institute
3600 Bay Area Boulevard
Houston TX 77058-1113
   281-486-2117
   281-486-2162 FAX
  treiman_at_lpi.usra.edu


-----Original Message-----
From: Bernd Pauli HD [mailto:bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de]
Sent: Friday, April 05, 2002 2:03 PM
To: meteorite-list
Subject: [meteorite-list] Tektite Identification


Jeanne wrote:

> We talk a lot about how to recognize meteorites in the field, and what
> to look for. What about tektites? Is it just visual cues, or do they do
> some other type of test to determine whether something is a tektite,
> or obsidian for instance?


Hello Jeanne and List,

1. Tektites have extremely low water contents
   (much lower than obsidian)
   Type of test => water content
2. Tektites usually do not occur on Earth
   in isolated areas but in strewn fields
   Type of test => strewn field
3. Compositional data:
   SiO2 - Al2O3 - FeO - MgO - CaO - NaO - K2O
   Type of test => percentage of the above compounds
4. Obsidian had a lot time to cool so crystals could
   and did grow. Tektites are not crystalline.
5. Scientists might also look for coesite and/or stishovite
   (the high-pressure silica polymorphs) because of the
   immense pressures involved when the tektites formed.


Best wishes,

Bernd

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Received on Fri 05 Apr 2002 03:18:32 PM PST