Glaucophane Prasinite from Viu Italy. Page 4.

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Above: plane polarized reflection, below: same with oblique illumination reflection. Mineral 12 is feldspar oligoclase, mineral 11 is calcite. See the bireflectance of the calcite (11) above.
Raman spectra of oligoclase at 532 and 633 nm.


Calcite on the transparent section. Picture below illustrates the high fluorescence of this calcite material with the green laser. The Raman edge filter is in place. The orange light coming from spot 11 b is fluorescence. It illuminates the whole section.
Raman spectra of calcite with both lasers. The same vibrational information can be obtained  but the signal to background ratio is much better with the Helium-Neon laser.