Tonatiuh, Aztec Sun God Museum de Kukturen, Basel

There are 22 eagle feathers surrounding 4 Ollin (earthquake)  which is the current era. This may be a reference to the 22-year binary sunspot cycle.

Stone of Moctezuma 1                                                Stone of Tizoc  

Museum of Anthroloogy, Mexico city                                                                                       Museum of Anthroloogy, Mexico city

Disco de Filadelfia                                          Stone of Sacrifices

National Stone/ Moctezuma's Throne

Museum of Anthroloogy, Mexico city

The Aztec Sunstone

Museum of Anthroloogy, Mexico city

Note the positions of holes for gnomons and other markings on the backdrop that may correlate to extremities of moon rise (photo: G. Stray). Tonatiuh's face is at the centre of the Ollin symbol.

More Detail: Great sunstone picture here NB: if the image is "not found", then click in the address bar and hit return/clear

Even more detail here

...And here

Possible original colour scheme....

Though this is more likely...just the central motif shown HERE...for the whole image, see Beyond 2012 colour plates.