Fig. 1. Virtual Museum of Minerals and Molecules displays of two phyllosilicate minerals: Expansible ferruginous soil smectite (left) after user-selection of octahedral- and tetrahedral-charge deficit sites and interlayer counterions, showing repeat layer structure, and kaolinite after user-activated button to select tetrahedral silica sheet in ball-and-stick mode (center), and in polyhedral mode (right, VRML format). At first glance, the silica of the kaolinite seem to be arranged in tessellating regular hexagons but the polyhedral view shows that they are in fact tessellating irregular hexagons.