Including Original "Paul H. Letters" Copyright © 1996-2018 Paul V. Heinrich - All rights reserved.

Saturday, 31 December 2011



In "tektites' at
Steve Kelland asked,

"Does anyone know if tektites ever devitrify?"

Tektites can devitrify over geological periods of time. 
However, the glass composing them typically reacts to 
weathering by either complete dissolution or etching instead
of devitrifying into clay. The devitrifcation of tektites into 
clays is currently only known to occur under conditions 
of limited water contact. 

Overall, tektites are exceptional for their high chemical 
resistance and long-term stability against devitrification.
In part, the presence of MgO in a simple silica melt 
containing CaO significantly suppresses the devitrifcation
of tektites.

For example, go read,

Mazer, J. J., J. K. Bates, J. P. Bradley, C. R. Bradley, and C. M. 
Stevenson, 1992, Alteration of tektite to form weathering 
products. Nature. vol. 357, no. 6379, pp. 573 - 576

Heide, K., G. Heide, and G. Kloessa, 2001, Glass chemistry of 
tektites. Planetary and Space Science. vol. 49, no. 8, pp. 839-844.

Happy New Year,

Paul Heinrich

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