Basalt Raman spectra.

            Wide field thin section of this rock

 

      Basalt thin section areas 1 and 2, crossed polars  and plane polarized views.

         Forsterite, augite, feldspar labradorite, magnetite and alteration products like amphiboles.

 

Plane polarized view.

      Area 1 is the high birefringence color augite.
   Area 2 is an alteration material. The spectrum is very similar to the one obtained on an altered olivine seen in a gabbro. Possibly the crystal enclosed in the augite was originally olivine. The spectrum does not give a single determination. It is a hydrated material which could be amphiboles (hastingsite) but the spectrum is also close to montmorillonite.
  The low birefringence twined material in area 3 is the feldspar labradorite.
 

    Basalt area 4: olivine

 

     Plane polarized view.

                 Spectrum in area 4 is forsterite. Note the green alteration product which fills up nearly entirely the olivine particle. It is the same for another green particle on the left.
 

        Area 5 and 6: large augite crystal with inclusions.

    Spectrum 6 is augite. The high birefringence filiform inclusion gives a  spectrum of augite with an additional peak which could be attributed to magnesite. It is of course difficult to be certain of this determination with only one peak but magnesite was the only matching mineral.
  

                Basalt opaque minerals: area 9 magnetite.

 
     Spectrum got with reduced power laser is magnetite which shows some signs of oxidation if the power is increased.