The tetragonal crystals are hemihedral with parallel faces ( like scheelite ), and at times of considerable size.
2.
Both crystallize in the ditrigonal pyramidal ( hemimorphic-hemihedral ) class of the rhombohedral system, possessing the same degree of symmetry as tourmaline.
3.
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.
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