The Asni agates from the Western Atlas Mountains are among the most interesting of all the varieties in Morocco. These usually relatively small agates, averaging 10 cm (4 inches) in diameter, show many intriguing structures and phenomena. 

The outer margin of reddish chalcedony is followed by banded white and grey toned agate. Fine fortification banding can may display the shadow-effect. Eye-agates are common. Stacked spherulitic agate layers (not water-level banding) are another unusual feature of these agates. Pseudomorphs and hemi-agates are not rare. Thus, Asni agates are one of the world’s most unusual varieties.

Since the year 2014 the area of Asni is belonging to the High Atlas national parc and research for agates here is now forbidden.