  We demonstrate that emulsion droplets stabilized by interfacial particles
become unstable beyond a size threshold set by gravity. This holds not only for
colloids but supra-colloidal glass beads, using which we directly observe the
ejection of particles near the droplet base. The number of particles acting
together in these ejection events decreases with time until a stable acorn-like
configuration is reached. Stability occurs when the weight of all remaining
particles is less than the interfacial binding force of one particle. We also
show the importance of the curvature of the droplet surface in promoting
particle ejection.
