Figure 3
The piling of the cubic `integrant molecules' which forms the pentagonal dodecahedron of pyrite. Notice the decrescence of the molecular lamellae in the proportion of 2:1, which leads to an interfacial angle at pq of 126° 52' 12´´, closely corresponding to that of the empirical crystal, viz 127° 56' 08´´ (Haüy, 1801BB11, Atlas).  [article HTML]