hemihedral การใช้

• The tetragonal crystals are hemihedral with parallel faces ( like scheelite ), and at times of considerable size.
• Both crystallize in the ditrigonal pyramidal ( hemimorphic-hemihedral ) class of the rhombohedral system, possessing the same degree of symmetry as tourmaline.
• Smaltite crystallizes in the cubic system with the same hemihedral symmetry as pyrite; crystals have usually the form of cubes or cubo-octahedra, but are imperfectly developed and of somewhat rare occurrence.