An early byzantine engraved almandine from the Garibpet deposit, Telangana state, India: Evidence for garnet trade along the ancient maritime silk road

An Early Byzantine almandine garnet engraved with a Christian motif and dated to the late sixth to eighth century offers insight into trade practices in antiquity. The gemstone was characterized by a combination of nondestructive analytical methods including electron microprobe, portable X-ray fluorescence, Raman spectroscopy, and optical microscopy. The chemical composition and zoning, in combination with the inclusion assemblage and the distinct distribution of inclusions between an inclusion-rich core and an inclusion-poor rim, indicated that the sample most likely originated from the large Garibpet deposit in Telangana State, India. The Byzantine intaglio thus furnishes evidence of garnet transport from the eastern Indian coast to the Mediterranean world during Early Medieval times. In so doing, it supports the interpretation of a sixth-century text by the Greek merchant and traveler Cosmas Indicopleustes, which describes the export of "alabandenum," a reference to garnet, from harbors on the southeast Indian shore along the ancient Maritime Silk Road. This idea is further buttressed by considering that garnet from the Garibpet deposit was used for bead production at the archaeological site of Arikamedu, one of the historical ports on the Coromandel Coast in southeast India. Conversely, a comparison with properties of the two predominant types of almandine used in Merovingian cloisonné jewelry shows that the characteristic mineralogical features and therefore the sources of these garnets set in Early Medieval jewelry were different.