Red power

Natural History, July, 2005 by Caitlin E. Cox

For millennia, the vivid orange-red pigment called vermillion has decorated pottery and preserved royal bones. Recently a team of geologists and archaeologists, led by Takeshi Minami, an environmental chemist at Kinki University in Osaka, Japan, traced large quantities of the prized pigment found in some central Japanese burial mounds to their source: local mines in the ancient Yamato kingdom, which flourished early in the first millennium A.D. in central Japan. Controlling access to those mines may have been an important element of Yamato realpolitik.

Funerary uses of vermillion, a form of mercuric sulfide, were common in China before they spread to western Japan. To find the source of the central Japanese vermillion, and thus help trace the region's political history, the investigators measured the relative abundances, or ratios, of two sulfur isotopes in the vermillion from twelve ancient mounds, because the ratios serve as indelible "birthmarks." Then they compared those isotope ratios with the ratios in vermillion from three central Japanese mines, as well as from an important ancient mine in Guizhou province, China.

Vermillion from the Chinese mine, they found, is high in sulfur-34; vermillion from the central Japanese mines, in and around the Yamato kingdom, is far richer in sulfur-32. Correlating the ratios showed that the vermillion in the western Japanese burial mounds originated in China, whereas the vermillion in the central Japanese mounds--datable to the time of the Yamato kingdom--was local.

One way the Yamato clan built alliances with neighbors was to distribute their stash of Chinese bronze mirrors. Handing out locally mined vermillion, say the investigators, may have been another. (Geoarchaeology 20:79-84, 2005)