The forms typically appearing on specimens of a mineral species or group, rarely all the forms permitted by its point group. Crystal habits range from highly diverse, e.g., calcite, to almost never showing crystal faces, e.g., turquoise. In addition to describing mineral habits with form names, e.g., prismatic, pyramidal, or tetrahedral, other names for appearances are used, e.g., fibrous, columnar, platy, or botryoidal. Intergrowths are given by specific description.