TRAPEZOHEDRAL CLASS (Trapezohedral-hemihedral.) Here there are the full number of axes of symmetry, but no planes or centre of symmetry. The general form { hkl } is bounded by eight trapezoidal faces and is the tetragonal trapezohedron.
Examples are nickel sulphate guanidine carbonate strychnine sulphate ( (C21H2LN202)2•H2SO4.6H20).