[meteorite-list] Tektite Identification

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:23 2004
Message-ID: <3CAE02E3.BA37705D_at_lehrer1.rz.uni-karlsruhe.de>

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
Received on Fri 05 Apr 2002 03:02:43 PM PST