Talc Chloritoid Garnet schist Raman Spectra (2)

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Glaucophane
The Glaucophane  is also highly pleochroic as can be seen on this thick section. The Raman spectrum has been recorded on the blue crystal shown by the arrow. See also absorption spectrum of Glaucophane.
 
The Raman spectrum obtained with our Raman microscope can be compared with a reference spectrum.
 
Rutile
To test the possibility of the present instrument to identify small crystals in a section, I have chosen this big Garnet crystal with small inclusions which seem to be Rutile. The  photograph below has been taken with a polarizer and analyzer nearly crossed and with  higher magnification to give a better view of the inclusions.
Details of the small inclusions.
 The Raman spectrum of the inclusions shown on the two pictures above confirms the nature of these small crystals to be Rutile. The spectrum obtained is not a pure Rutile spectrum, some Garnet peaks remain due to the small size of the Rutile particles. This is probably due to the lack of spatial resolution of this instrument in a direction parallel to the laser beam.
 
Quartz in Garnet
Another inclusion in the Garnets is shown in the picture above. In this case, the section is sufficiently thin to allows the laser beam to cross the section without touching the Garnet material.
 
The Raman spectrum of this inclusion is evidently Quartz.
 
Apatite
Another inclusion in Garnet which seems to be thinner than the section has also be measured (red arrow).
 
The spectrum of this inclusion is evidently dominated by the garnet material. The additional peaks  present in the spectrum (black arrows) have been identified as Apatite, a finding also compatible with the low birefringence of this crystal.

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