CLINOHEDRAL CLASS (Hemihedral ; Domatic.) Crystals of this class are symmetrical only with respect to a single plane. The only form which is here geometrically the same as in the holosymmetric class is the clino pinacoid { oio } . The forms perpendicular to the plane of symmetry are all pedions, consisting of single planes with the indices { Ioo},t ioo},tooi}, {ooi},(hol},etc. The remaining forms, t hko} , { okl } and t hkl 1, are domes or "gonioids" (ycwLa, an angle and Eiaos, form), consisting of two planes equally inclined to the plane of symmetry.
Examples are potassium tetrathionate hydrogen tri-sodium hypophos phate ; and amongst minerals, clinohedrite (H2ZnCaSiO4) and scolectite.