A Treatise on Crystallography

adjacent faces adjacent poles angle between normals arcs joining arranged with respect circle cleavable parallel cos PX cos PY cos cot PY distance dodecahedron equal angles equations face hkl faces of 100 form bounded form h kl form with inclined forms with parallel h k l hemihedral form Hence the crystal holohedral form inclined asymmetric faces inclined faces indices h intersect inverse form Let the symbols meet the surface nearest pole number of faces octahedron odd number parallel faces parameters perpendicular pole of hkl poles of 100 poles of h prismatic system projection be divided ratios referred to OX rhombohedral system sin PQ sin QR sphere of projection symmetric faces symmetrically arranged twin axis twin crystal u v w Whence zone zone-circle