Illustration of the Israeli chemist Dan Shechtman (born 1941). Shechtman is best known for his work on quasicrystals, for which he was awarded the 2011 Nobel Prize in Chemistry. Quasicrystals are a type of solid structure where there is long-range order with five-fold symmetry, which results in a non-repeating pattern. The crystal patterns, first discovered in aluminium-manganese alloys in 1984, are generated according to rules related to the Fibonacci sequence and the golden ratio.