Rock crystal is a form of quartz. The Aztecs received it in tribute from the Huaxtepec province in the Valley of Morelos. Working it into objects, particularly those as precisely matched as the Bliss Collection’s ear spools, would have been challenging, because rock crystal is even harder than obsidian. In this regard it is similar to jade, both rating a 6.5–7.0 on the Mohs scale, but rock crystal lacks the structural toughness of jade, making it more difficult to work. Thus these rock crystal ear ornaments represent a high degree of artisanship and many hours of work.

Technical examination of this pair of ear ornaments revealed that a modern adhesive was used to attach the gold disks. This observation could indicate that either the ancient composite form underwent modern restoration or it is a modern composition.
We do know, however, that ear ornaments of rock crystal and gold were popular in Postclassic times. The Aztec Empire was in the process of expanding when the Spaniards arrived in the New World. In typical fashion, the Aztec vanguard merchants would establish gift exchange relations between the Aztec king and the local elites, and these relations would then, through diplomatic or military actions, become political ties as the target province was brought into tributary status. By ca. ad 1500, this process was beginning in the region of Acalan, along the southwestern coast of the Yucatan peninsula, and Emperor Ahuitzotl’s traders brought gifts that were worthy of royal families—fine textiles of palace quality and “what the princesses required: golden bowls for spindles, and ear plugs of gold and of rock crystal” (Sahagún 1959 [1569]: 18).

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. 25, cat. 117.

Bliss, Robert Woods 1947 Indigenous Art of the Americas: Collection of Robert Woods Bliss. National Gallery of Art, Smithsonian institution, Washington, D.C., p. 20, 96, cat. 87.

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. cat. 69, pl. L.

"Indigenous Art of the Americas", National Gallery of Art, Washington DC, April 1947 to July 1949 and January 1956 to July 1962.

Purchased from Charles L. Morley, 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.