illustrates three imaging modes for the reflected light microscope:
1. The plane polarized light (LPNA) gives an idea of the reflection
coefficient of the minerals. It is used mainly to recognize the opaque
minerals. For transparent materials, the reflected light intensity
varies according to the refraction index of the mineral. This kind of
micrograph is very useful for the Raman microscopy to distinguish
different minerals present at the surface.
2. The crossed polars view (LPA) gives an insight into the material
(internal reflections). For opaque minerals, it indicates the anisotropy
of the mineral, for the transparent crystals like those figured below,
it is an internal view of the section.
3. Differential interference contrast in reflection (DIC) is an
enhanced topography of the surface. It looks like an amplification of
the distances perpendicular to the image plane. This view is obtained by
inserting a Wollaston prism in the accessory slot of the microscope
between crossed polars.