A quartz vein in the Rawhide Mountains (Mohave County) contained a small fraction of plagioclase. Extreme mylonitic shearing in the grey quartz is invisible, but plagioclase feldspar crystals were smeared out by shearing and are now thin sheets of broken and disaggregated crystals that are as little as a few tens of microns thick. (Photo by Jon Spencer, 2011.)
Scott, R.J., 2004, Geologic maps and cross sections of selected areas in the Rawhide and Buckskin Mountains, La Paz and Mohave counties, Arizona, .v. 1.0: Arizona Geological Survey Contributed Map CM-04-D, map scale 1:10,000, 11 p. and 10 map sheets. https://library.azgs.arizona.edu/item/AGCM-1552426976996-391
Spencer, J.E. and Reynolds, S.J. (eds.), 1989, Geology and Mineral Resources of the Buckskin and Rawhide Mountains, West Central Arizona. Arizona Geological Survey Bulletin 198, 272 p. https://library.azgs.arizona.edu/item/AGSB-1552427346215-773
Photographer: Jon Spencer
Photo Date: 2011