Raman spectroscopy is becoming an increasingly important investigative tool in modern geosciences. So it has been applied in the examination of a variety of materials, including meteoritic and igneous rocks, as well as natural and synthetic minerals and crystals.
This is not least due to the many advantages of Raman spectroscopy, like very fast measurements, small spot size or different samples consistency.
One main investigation area are meteorites, because new space mission programs to Moon and Mars are underway. In these new missions, robots are equipped with analytical instruments to probe the chemistry and constitution of the materials on the surface of the respective bodies. One of the promising mobile techniques is Raman spectroscopy. Therefore, the experience and measurement of comparable samples like meteorites, basalts or ophiolitic material helps us a lot. Several types of different meteorites have already been investigated here, for example, those recovered from the Neuschwanstein, Almahatta Sitta, Braunschweig or Tscheljabinsk fall. Furthermore, we started to investigate Meteorites from the Moon and Mars.
Raman methods can also help to study mineral compositions, because the spectra can aid in the classification, based upon crystal structure and mineral composition. In combination with electron microprobe, it is a perfect tool to characterize different polytypes and polymorphs. As such, it has been possible to distinguish between graphite, graphene and diamond within some of our meteorite samples, and between coesite, stishovite and other quartz polymorphs, present. These critical data provide pressure and temperature information for the meteorite and its parent body.
Melanie Kaliwoda1, Malte Junge1, Felix Hentschel1, Wolfgang W. Schmahl1, Fabian Dellefant2, Claudia Trepmann2
1Mineralogical State Collection Munich, SNSB and Ludwig Maximilians University, LMU, Germany; 2Ludwig Maximilians University, LMU, Germany