File:Sand under electron microscope.jpg

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DescriptionSand under electron microscope.jpg	Grains of so-called “Ottawa Silica Sand” under an electron microscope. Magnification 150x. “Ottawa Sand” is a by-product of hydraulic mining of Ordovician orthoquartzites of the St. Peter Sandstone Formation of the Paleozoic intracratonic Illinois Basin.
Date	not specified
Source	http://mix.msfc.nasa.gov/abstracts.php?p=743
Author	NASA
Permission (Reusing this file)	US government, public domain

File:Sand under electron microscope.jpg

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