A Mueller Matrix Imaging Ellipsometer system is operated in transmission and used to study nematic textures
in colloidal dispersions of synthetic Na-fluorohectorite clay platelets in solution. It is clearly observed that the
anisometric particles organize into phases with strong birefringence, which results in a strong retardance. The
Mueller matrix imaging technique supplies an image of the retardance matrix, even in the presence of other
effects such as light scattering and diattenuation. The spatial variation of the absolute value of the retardance,
the orientation of the fast axis of the retardance, the total diattenuation and the orientation of the diattenuation
are presented. In particular, from knowledge of the anisotropic shape of the particles, the orientation of the
particles within ordered domains, and the density of the particles within the domains are spatially determined.
The experiments are based on adding synthetic clay particles into a solution contained in a thin rectangular glass
container. Upon letting gravitation act on the sample, different phases appear after a few weeks. One phase
contains nematic textures and we are able to determine the ordering and also estimate the density of the
domains/texture within the phase, in addition to estimating the local order within a domain with an image
resolution of 12 μm.