  We report on the critical properties of minimaly-polydisperse crystals,
hexagonal in 2d and face-centered cubic in 3 dimensions, at the isostatic
jamming point. The force and gap distributions display power-law tails for
small values. The vibrational density of states (VDOS) is flat. The scaling
behavior of forces of extended floppy modes and the VDOS are universal and in
agreement with an infinite-dimensional mean-field theory and maximally
amorphous packings down to 2 dimensions. The distributions of gaps and forces
of localized floppy modes of near-crystals appear non-universal. A small
fraction of normal modes exhibit partial localization at low frequency. The
majority of normal modes is delocalized exhibiting a characteristic inverse
participation ratio scaling with frequency. The packing fraction and order at
jamming decay linearly and quadratically respectively with polydispersity down
to the maximally amorphous state.
