Mineralogical composition of the meteorite El Pozo (Mexico): a Raman, infrared and XRD study

Spectrochim Acta A Mol Biomol Spectrosc. 2011 Dec;83(1):437-43. doi: 10.1016/j.saa.2011.08.061. Epub 2011 Aug 31.

Abstract

The Raman (RMP), infrared (IR) and XRD analysis have been applied to the examination of mineralogical composition of El Pozo meteorite (an ordinary chondrite L5 type; village Valle of Allende, founded in State of Chihuahua, Mexico: 26°56'N and 105°24'W, 1998). RMP measurements in the range of 100-3500 cm(-1) revealed principal characteristic bands of the major minerals: olivine, two polymorph modifications of pyroxene (OPx and CPx) and plagioclase. Some bands of the minor minerals (hematite and goethite) were also identified. All these minerals were clearly distinguished using IR and XRD techniques. XRD technique has shown the presence of some metallic phases such as kamacite and taenite as well as troilite and chromite. These minerals do not have characteristic Raman spectra because Fe-Ni metals have no active modes for Raman spectroscopy and troilite is a weak Raman scatterer. Raman mapping microspectroscopy was a key part in the investigation of El Pozo meteorite's spatial distribution of the main minerals because these samples are structurally and chemically complex and heterogeneous. The mineral mapping by Raman spectroscopy has provided information for a certain spatial region on which a spatial distribution coexists of the three typical mineral assemblages: olivine; olivine+orthopyroxene; and orthopyroxene.

MeSH terms

  • Ferric Compounds / analysis
  • Iron Compounds / analysis
  • Magnesium Compounds / analysis
  • Meteoroids*
  • Mexico
  • Minerals / analysis
  • Minerals / chemistry*
  • Silicates / analysis
  • Spectrophotometry, Infrared
  • Spectrum Analysis, Raman
  • X-Ray Diffraction

Substances

  • Ferric Compounds
  • Iron Compounds
  • Magnesium Compounds
  • Minerals
  • Silicates
  • pyroxene
  • goethite
  • ferric oxide
  • olivine