A city at the crossroads
In the fertile Surkhandarya river valley of southern Uzbekistan lies Dalverzintepa, the remains of a fortified city that flourished between the 1st and 4th centuries CE. Once a major urban center of the Kushan Empire, the 47-hectare site was enclosed by a defensive wall nearly 2.5 kilometers long and up to 10 meters thick. Systematic excavations, which began in the 1960s under Soviet archaeologists like Galina Pugachenkova, uncovered a planned city with a citadel, residential quarters, craft workshops, and multiple religious structures, including a Bactrian shrine and two Buddhist temples.
Within one of these Buddhist complexes, archaeologists found numerous sculptures depicting buddhas and bodhisattvas. While many were made of painted clay and plaster, a number of smaller, detailed figures were carved from elephant ivory. For centuries, these carvings appeared as plain, monochrome objects. The original bright polychromy had long since faded from view, leaving only microscopic residues on the porous ivory surface. Modern analytical methods, however, have revealed the true, colorful nature of these ancient artworks and the vast trade networks required to create them.
Reading invisible pigments
Scientific analysis of the Dalverzintepa ivories uses non-destructive spectroscopic techniques to identify the chemical composition of the faint pigment traces. Methods like X-ray fluorescence (XRF) bombard the artifact with X-rays, causing the atoms in the original paint to emit their own characteristic energy signatures. This process allows researchers to map the elements present—like copper, iron, or lead—without ever touching or damaging the sculpture itself.
This elemental fingerprinting showed an international palette. Blue pigments are made from ground lapis lazuli, a semi-precious stone whose only known ancient source is the Sar-i-Sang mines in the Badakhshan region of modern Afghanistan, over 300 kilometers away through mountainous terrain. The deep red and pink tones come from a cochineal-based dye. This crimson colorant is produced from the crushed bodies of scale insects, and the specific type used was sourced from the Mediterranean region, thousands of kilometers to the west. The analysis shows the Kushan artisans had access to the most exclusive materials of their day, brought to Bactria via the complex network of trade routes often called the Silk Road. The Kushan Empire's strategic position, connecting the Roman west, the Indian subcontinent, and the Chinese east, made it a powerful hub for the exchange of luxury goods, raw materials, and new ideas.