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.