Raman Spectra of Tourmaline

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Pink tourmaline crystal with polarizer along optic axis and in a direction perpendicular to it. Generally for tourmalines the color intensity is higher when the polarizer is perpendicular to OA. Sometimes the pleochroism could be very intense. In some cases, the Raman spectrum in the direction perpendicular to OA is very weak and cannot be recorded. For dark Dravite crystals only spectra  parallel to optic axis have been reproduced here.




Coarse rock with Elbaite (green) and Quartz as can be seen on  the Raman spectra below. Spectra of the green prismatic Elbaite crystal imaged below are also included. White material is quartz.

The Raman spectra of the Elbaite samples presented here are very similar especially the spectra with laser light polarized along optic axis even if the color is different. Spectra perpendicular to OA exhibit some differences mainly in the bands intensities.



Green prismatic Elbaite crystal: spectrum above.

Yellow green Liddicoatite: spectrum below.

Yellow Dravite.

The Raman spectrum of this crystal is partly obscured by fluorescence.


Some Yellow and black tourmalines Dravite spectra polarized parallel to optic axis.


Good resolved spectra of Liddicoatite.

Spectra of the OH stretching vibrations of the green-brown Elbaite section shown above. Figure shows clearly the pleochroism of the OH band. The triplet of the OH vibrations is also present in the second harmonic spectrum recorded before in the NIR wavelength region. The triplet was obtained only for crystal orientation with optic axis parallel to polarizer direction.


Tourmalines OH Band.


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