The crystallographic restriction theorem in its basic form was based on the observation that the rotational symmetries of a crystal are usually limited to 2-fold, 3-fold, 4-fold, and 6-fold. However, quasicrystals can occur with other diffraction pattern symmetries, such as 5-fold; these were not discovered until 1982 by Dan Shechtman.
Dan Schechtman revealed 5-fold pattern.
( z1 reveal :ARG0 ( z2 person :name ( z3 name :op "Dan" :op "Schechtman" ) ) :ARG1 ( z4 pattern :mod ( z5 product-of :op 5 :op ( z6 pattern ) ) ) )