gems, history of gemology, gem trade, Persia, Central Asia, history of gem trade, Rome, India, Indian lapidary

The major routes of early maritime trade in the Red Sea and northern Indian Ocean were distinctive, characterized by the long-term movement of specific exchange commodities and their connection to particular market towns, ports, maritime conditions, tribes, and peoples. Evidence from the Periplus Maris Erythraei suggests that these trade zones were sufficiently separated by distance and resources—especially in terms of export commodities—to function as distinct but interacting exchange regions. This dual nature of separation and interactivity is reflected in the presence of well-established maritime routes along which specific trade goods circulated. Salles (1993: 506–513) describes these ancient sea routes as ‘segments’ or ‘trade units,’ whose use and control were shaped by market demands, shifts in political power, and navigational knowledge. Among these, the longest and most significant was the direct sea route from the Egyptian Red Sea coast to India.