The Aztec lapidary artists were fascinated with hard stones of different colors and shiny surfaces. Obsidian was used mainly for jewelry, such as labrets and earspools. An object such as this superb mask is therefore quite rare, reflecting the great skill of Aztec stone carvers. Considerable attention was given to realistic detail, with its deep set almond eyes, graceful curve of the brows, sensuous lips and crease lines parallel to the nose. The rectangular ears are narrow and very delicately carved. They serve to make the forehead seem even broader and contrast nicely with the horizontal slits of the eyes. Masks were used as "mediums" for spiritual beings in need of a temporary physical abode. When an Aztec ruler was ill, masks were placed on the idols of the gods in the temples, possibly to either shield the ruler from harmful influence, or to provide a "channel of communication" between man and deity. This extraordinary mask certainly has qualities that are indefinable; possessing a character and persona beyond our understanding, except simply to enjoy its beauty.