¹Steven J. Jaret,¹Brian L. Phillips,²David T. King Jr,¹Tim D. Glotch,³Zia Rahman,⁴Shawn P. Wright
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12745]
¹Department of Geosciences, Stony Brook University, Stony Brook, New York, USA
²Department of Geosciences, Auburn University, Auburn, Alabama, USA
³Jacobs—NASA Johnson Space Center, Houston, Texas, USA
⁴Planetary Science Institute, Tucson, Arizona, USA
Published by arrangement with John Wiley & Sons

Coesite has been identified within ejected blocks of shocked basalt at Lonar crater, India. This is the first report of coesite from the Lonar crater. Coesite occurs within SiO2 glass as distinct ~30 μm spherical aggregates of “granular coesite” identifiable both with optical petrography and with micro-Raman spectroscopy. The coesite+glass occurs only within former silica amygdules, which is also the first report of high-pressure polymorphs forming from a shocked secondary mineral. Detailed petrography and NMR spectroscopy suggest that the coesite crystallized directly from a localized SiO2 melt, as the result of complex interactions between the shock wave and these vesicle fillings.