The impressive motif of this necklace is presented by 18 nearly identical carved shell beads in the shape of skulls, separated from one another by simple disk spacer beads. All were carved from thick shell that has been identified as Spondylus, possibly Spondylus princeps. Traces of red pigment, perhaps cinnabar, are present in a few crevices of some skulls; other skulls still bear eye inlays of hematite. Some of the eyes are partly broken, revealing that they were formed in the shape of a round-headed pin.
The symbolism of this necklace plays with two concepts: the fertile waters of the home of the shell and the fertility ensured by human sacrifice. The carved beads suggest the dry, bleached crania of sacrificial victims as they were displayed in the temple complex on the public skull rack (tzompantli in Nahuatl). The cord passing through the skulls mimics the way in which skulls were arrayed on wooden poles on the rack. Life and death are thus interlinked and dependent on each other.
The use of the skull motif in a necklace also occurs in sculptures of Aztec deities. Female deities, such as Coatlicue and the Tzitzimime, commonly wear skulls as part of the ornaments of their necklaces. Such deities brought together death imagery and the concept of fertility.

If the assemblage is complete as originally created, the 18 skulls conform to Mesoamerican numerological concepts. The solar year was organized into 18 periods of 20 days each, each of the 18 units with its own name. Thus each skull may symbolize a period in which cycles of life and death continually revolve, and the high-ranking person who wore the necklace would have been a fierce, walking tzompantli.

Alcina Franch, José, Miguel León Portilla and Eduardo Matos Moctezuma 1992 Azteca Mexica. Colección Encuentros. Serie Catálogos. Lunwerg Editores, Barcelona. p. 160, pl. XXXVIII.

Benson, Elizabeth P. 1963 Handbook of the Robert Woods Bliss Collection of Pre-Columbian Art. Dumbarton Oaks, Trustees for Harvard University, Washington, D.C., p. 24, cat. 115.

Bliss, Robert Woods 1947 Indigenous Art of the Americas: Collection of Robert Woods Bliss. National Gallery of Art, Smithsonian institution, Washington, D.C., p. 24, 119, cat. 116.

Bliss, Robert Woods 1957 Pre-Columbian Art: The Robert Woods Bliss Collection. Text and Critical Analyses by S. K. Lothrop, Joy Mahler and William F. Foshag. Phaidon, New York. p. 243, cat. 60, pl. XLVI.

"Indigenous Art of the Americas", National Gallery of Art, Washington DC, April 1947 to March 1952 and February 1954 to July 1962.

"Azteca Mexica, Las Culturas del Mexico Antiguo", Museo de America, Madrid, 1992.

Purchased from John Wise, New York (dealer), by Robert Woods Bliss, 1947.

Robert Woods Bliss Collection of Pre-Columbian Art, Washington, DC, 1947-1962.

Dumbarton Oaks Research Library and Collection, Pre-Columbian Collection, Washington, DC.