  Evidence is presented for infinite charge mobility in natural crystals of
muscovite mica at room temperature. Muscovite has a basic layered structure
containing a flat monatomic sheet of potassium sandwiched between mirror
silicate layers. It is an excellent electrical insulator. Studies of defects in
muscovite crystals indicated that positive charge could propagate over great
distances along atomic chains in the potassium sheets in absence of an applied
electric potential. The charge moved in association with anharmonic lattice
excitations that moved at about sonic speed and created by nuclear recoil of
the radioactive isotope K40. This was verified by measuring currents passing
through crystals when irradiated with energetic alpha particles at room
temperature. The charge propagated more than 1000 times the range of the alpha
particles of average energy and 250 times the range of channelling particles of
maximum energy. The range is limited only by size of the crystal.

Materials Science;Pattern Formation and Solitons