Polarized spectra were not generally acquired.  Most data are taken with depolarized laser light incident on the specified face. On the Renishaw instrument, a quartz double wedge depolarizer located before the light enters the microscope was used for this purpose. With the Kaiser instrument, the light was completely depolarized in the fiber optic that directs laser light to the sample.

  In some cases, orientational effects with crystallographically aligned samples are pronounced  Orientations are specified several ways.  _|_a, _|_b, _|_c correspond to crystal faces (100), (010), (001).  See the example below for further information.