Coesite from the Richat Dome, Mauritania: A Misidentification
R. F. Fudali 1
1 Department of Mineral Sciences, Smithsonian Institution, Washington, D.C. 20560
The "shattered sandstone" from Richat reported to contain coesite is a tectonic breccia and probably represents a shear zone developed during the structural doming. An optical and x-ray examination of concentrates from this breccia demonstrated that the supposed x-ray reflections of coesite are actually due to barite, introduced into the permeable crushed zone by groundwater.