  Despite the omnipresence of colloidal suspensions, little is known about the
influence of shape on phase transformations, especially in nonequilibrium. To
date, real-space imaging results are limited to systems composed of spherical
colloids. In most natural and technical systems, however, particles are
non-spherical and their structural dynamics are determined by translational and
rotational degrees of freedom. Using confocal microscopy, we reveal that
suspensions of ellipsoidal colloids form an unexpected state of matter, a
liquid glass in which rotations are frozen while translations remain fluid.
Image analysis unveils hitherto unknown nematic precursors as characteristic
structural elements of this state. The mutual obstruction of these ramified
clusters prevents liquid crystalline order. Our results give unique insight
into the interplay between local structures and phase transformations. This
helps to guide applications such as self-assembly of colloidal superstructures
and also gives first evidence of the importance of shape on the glass
transition in general.
