Quasicrystal

Part of speech: noun

Definitions

1. A solid with a distinct atomic arrangement that exhibits both order and a lack of repeating patterns while displaying unique symmetrical properties
2. This material features an atomic structure that fills space irregularly and shows non-periodicity, setting it apart from typical crystalline forms
3. A solid form characterized by an atomic arrangement that is well-organized yet does not repeat periodically, showing unique patterns of symmetry

Etymology: Dan Shechtman's 1984 discovery of a crystal whose atoms formed a pattern with five-fold symmetry was so unexpected that chemists initially refused to accept it, since crystallography held that such symmetry was impossible for a periodic lattice. The name that came out of that controversy was built from two ordinary English pieces. "Quasi" comes from Latin "quasi," meaning "as if" or "almost," itself from "quam" ("as, how") combined with "si" ("if"). Attached to "crystal," it describes a solid that behaves like a crystal, with ordered structure and sharp diffraction patterns, but lacks the repeating unit cell that defines ordinary crystals.