Two tiles: square + 45° rhombus
Inflation factor: 1+√2 (silver ratio)
8-fold quasicrystalline symmetry
Inflation factor: 1+√2 (silver ratio)
8-fold quasicrystalline symmetry
Square
Rhombus
The Ammann–Beenker tiling was discovered independently by Robert Ammann and Johan Beenker in the 1970s–80s. Quasicrystals with 8-fold symmetry (otherwise forbidden in periodic crystals) have been found in Al–Mn–Si alloys.