  We investigate the influence of Unruh radiation on matter-wave interferometry
experiments using neutral objects modeled as dielectric spheres. The Unruh
effect leads to a loss of coherence through momentum diffusion. This is a
fundamental source of decoherence that affects all objects having
electromagnetic interactions. However, the effect is not large enough to
prevent the observation of interference for objects of any size, even when the
path separation is larger than the size of the object. When the acceleration in
the interferometer arms is large, inertial tidal forces will disrupt the
material integrity of the interfering objects before the Unruh decoherence of
the centre of mass motion is sufficient to prevent observable interference.
