You should be able to differentiate phases of liquid crystals. However, I have never done that myself. You could check the following PNAS publication and also the attached pdf thesis (downloaded from website) for further information. 

http://www.pnas.org/content/102/21/7438.full.pdf+html

There is a little work in this area, but I suspect other methods would normally be simpler

you may like to look at this paper

AFM, X-ray diffraction and optical microscopy studies of faceted droplets of a thermotropic bicontinuous cubic mesophase

By: Even, C; Gourbil, A; Impeor-Clerc, M; et al.

CHEMPHYSCHEM Volume: 3 Issue: 12 Pages: 1031-1034 Published: DEC 16 2002

Paul