Hello List, Someone asked in a private mail: "What's mosaicism?"
Here's an excellent explanation by O.R. Norton - it can be found in "Cambridge Encyclopedia of Meteorites", p. 344: "A characteristic of a mineral crystal seen microscopically under crossed polarizers in which extinction is not uniform but checkered into a mosaic pattern due to small irregularities within the crystal. This occurs when the crystal has been distorted by shock metamorphism. Mosaicism is an indicator of shock effects produced by an impacting body." I am glad someone asked this question as it may be the answer to my own question about those dark bands in Tatahouine: "Does anybody have any information about the nature of the dark bands that are visible not only in this backlit specimen but usually in all Tatahouine specimens? Shock darkening?" Best wishes, Bernd ______________________________________________ Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
