  Crystals, as quantum objects typically much larger than their lattice
spacing, are a counterexample to a frequent prejudice that quantum effects
should not be pronounced at macroscopic distances. We propose that the Einstein
theory of gravity only describes a fluid phase and that a phase transition of
crystallization can occur under extreme conditions such as those inside the
black hole. Such a crystal phase with lattice spacing of the order of the
Planck length offers a natural mechanism for pronounced quantum-gravity effects
at distances much larger than the Planck length. A resolution of the black-hole
information paradox is proposed, according to which all information is stored
in a crystal-phase remnant with size and mass much above the Planck scale.
