• DOI:10.2138/am-2002-0728
• Corpus ID: 129400258

Characterization of a high-pressure phase of silica from the Martian meteorite Shergotty

@article{Dera2001CharacterizationOA,
  title={Characterization of a high-pressure phase of silica from the Martian meteorite Shergotty},
  author={Przemyslaw K. Dera and Charles T. Prewitt and Nabil Z. Boctor and Russell J. Hemley},
  journal={American Mineralogist},
  year={2001},
  volume={87},
  pages={1018 - 1023}
}

• P. Dera, C. Prewitt, +1 author R. Hemley
• Published 1 July 2002
• Materials Science, Geology
• American Mineralogist

Abstract Recently, there has been substantial interest in post-stishovite high-pressure polymorphs of SiO2, discovered as extraterrestrial minerals, or synthesized in the laboratory. Previous investigators reported the presence of “α-PbO2-like” and “baddeleyite-like” SiO2 in the Martian meteorite Shergotty, and also the synthesis of an a-PbO2-like phase at pressures of 60-80 GPa in a laser-heated diamond anvil cell. To provide definitive information about the nature of the natural “a-PbO2 phase,” we recovered a small sample from the Shergotty meteorite, obtained powder X-ray diffraction patterns, and performed a Rietveld refinement of the structure. The resulting cell parameters and space group are a = 4.097(1) Å, b = 5.0462(9) Å, c = 4.4946(8) Å, and Pbcn. The structure refinement confirms that this sample does have the α-PbO2 structure