:I'm not absolutely sure that this is what the OP is talking about, but he or she may want to look at the lists in our pleochroism article . talk ) 12 : 23, 4 November 2012 ( UTC)
32.
In an optical mineralogy analysis, petrologists analyze thin sections of rock samples using a petrographic microscope, where the minerals can be identified through their different properties in plane-polarized and cross-polarized light, including their birefringence, pleochroism, geochemical evolution of rock units.
