De International Union of Crystallography hod auf dees hi, das as Phenomän nochgwisn worn is, de vorige modell-lastige Definition von den wos a Krisdoj is ("A crystal is substance in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating three dimensional pattern") umgeendat in a phenomen-basiade: "By 'Crystal' is meant any solid having an essentially discrete diffraction pattern."