  We study the phase ordering dynamics of a two dimensional model colloidal
solid using molecular dynamics simulations. The colloid particles interact with
each other with a Hamaker potential modified by the presence of equatorial
"patches" of attractive and negative regions. The total interaction potential
between two such colloids is, therefore, strongly directional and has
three-fold symmetry. Working in the canonical ensemble, we determine the
tentative phase diagram in the density-temperature plane which features three
distinct crystalline ground states viz, a low density honeycomb solid followed
by a rectangular solid at higher density, which eventually transforms to a
close packed triangular structure as the density is increased further. We show
that when cooled rapidly from the liquid phase along isochores, the system
undergoes a transition to a "strong glass" while slow cooling gives rise to
crystalline phases. We claim that geometrical frustration arising from the
presence of many crystalline ground states causes glassy ordering and dynamics
in this solid. Our results may be easily confirmed by suitable experiments on
patchy colloids.
