Crystal structure of kaolinite, an example of a dioctahedral sheet silicate with a TO structure.
Dark blue: silicate tetrahedra; light blue: Al-octahedra; red: O; green: OH-
The model was produced in the freeware [Vesta](http://jp-minerals.org/vesta/en/), using crystallographic data from Bish and Von Dreele (1989), downloaded from the [American Mineralogist Crystal Structure Database](http://rruff.geo.arizona.edu/AMS/amcsd.php).