  The transport of heavy, neutral or charged, point-like particles by
incompressible, resistive magnetohydrodynamic (MHD) turbulence is investigated
by means of high-resolution numerical simulations. The spatial distribution of
such impurities is observed to display strong deviations from homogeneity, both
at dissipative and inertial range scales. Neutral particles tend to cluster in
the vicinity of coherent vortex sheets due to their viscous drag with the flow,
leading to the simultaneous presence of very concentrated and almost empty
regions. The signature of clustering is different for charged particles. These
exhibit in addition to the drag the Lorentz-force. The regions of spatial
inhomogeneities change due to attractive and repulsive vortex sheets. While
small charges increase clustering, larger charges have a reverse effect.
