gems, glyptic, engraved gems, agate, cameo, intaglio, carnelian, agate sources, provenance, origin

Agate was one of the ancient world’s premier prestige goods, especially the red-orange variety known as carnelian. The stone was utilized by and traded between societies from Africa to eastern Asia (Inizan 1993; Insoll et al. 2004; Theunissen et al. 2000). In this paper, we present the results of a series of instrumental neutron activation analyses (INAA) of agate samples and artifacts from sources and/or sites in the Indus, Helmand, and Thailand regions. This study represents the beginning of a broad-scale, long-term project aimed at identifying Old World agate sources and the regional and inter-regional trade networks through which this important stone was exchanged in both raw and finished form. Our main goal at this initial stage was to determine if agate sources could be effectively differentiated from one another using INAA-derived data. To this end, sets of samples representing multiple geologic occurrences were analyzed at two different research reactors – the University of Wisconsin’s Nuclear Reactor (UWNR) and the University of Missouri Research Reactor (MURR). It was found that good-to-excellent (≈ 85 % to 95 %) statistical separation between different sources could be achieved when the INAA results from these facilities were evaluated using canonical discriminant analysis (CDA). A set of agate artifacts from the Indus Civilization sites of Harappa and Nagwada along with a set of carnelian beads of unknown archaeological provenience were also analyzed. Although the geologic dataset they were compared to is, at present, limited, the results both support and challenge past assumptions regarding the acquisition of agate in proto-historic South Asia.