Granitex is Sculpey's faux stone recipe of polymer clay. It is essentially Sculpey III, but with tiny fibers mixed in to create the look of stone.
Granitex can be mixed with other clays to add texture to the new clay body. It comes in eight pastel tones, or can be mixed with other clays to create new colors.
Granitex can be used in the same ways as regular clay, though it is specially designed to have a unique texture and to mimic the look of stone. Blue Granitex is also a good mimic of denim.