Some show external carved decoration. Generally have flaring sides. Typical of the Late Horizon. They are highly polished and may have external carved designs or may be in the shape of heads. They are black to greenish-black and highly polished.
Larger examples tend to be of lighter- colored stone while the smaller ones are of dark stones.
Some, especially those carved of diorite, have snake-like traits. The carved surface is highly polished. The upper surface has a patina. They range from 20 cm. Very rare, they have straight sides and incised or high- relief decoration.