Crystal structure of chlorite, an example of a sheet silicate with a TOT + O structure.
Dark blue: tetrahedral sites (Si, Al); light blue: octahedral sites (Mg, Fe, Al); red: O; green: OH-
The model was produced in the freeware [Vesta](http://jp-minerals.org/vesta/en/), using crystallographic data from Lister and Bailey (1967), downloaded from the [American Mineralogist Crystal Structure Database](http://rruff.geo.arizona.edu/AMS/amcsd.php).