How did Dan Shechtman discover quasicrystals?

In 1982, while on sabbatical at the National Bureau of Standards, Daniel Shechtman was researching the metallurgical properties of aluminum-manganese alloys. His discovery occurred after he heated the mixture and rapidly cooled it into a solid state.1

Using an electron microscope, Shechtman observed that the alloy displayed fivefold symmetry—a structure that repeats every 72°. At the time, this was considered impossible for crystals, as such symmetry cannot form a regular, repeating lattice. He identified the structure as aperiodic, meaning it followed mathematical rules but never repeated itself.1

Shechtman faced significant professional resistance for his findings, as the scientific community long held that such structures could not exist. It was not until 1984 that he published his work, and the term quasicrystal was coined by physicists Paul Steinhardt and Dov Levine. He was eventually vindicated in 1987 when larger samples allowed for confirmation via X-rays, leading to his 2011 Nobel Prize in Chemistry.1