In the Fukuoka Prefecture of Japan, researchers have unearthed a cache of mica-flecked clay pendants within a Yayoi period settlement. These ornaments, found in a circular arrangement around a central granary, are believed to have been worn during Spring-Seed rites, where the reflective properties of the mica were used to mirror the sun and invite its warmth into the planting soil. This discovery predates the introduction of more complex bronze mirror rituals in the region.
The excavation also revealed that each pendant was individually inscribed with symbols representing different local cereal crops, such as millet and dry-land rice. These findings suggest that communal identity during the Yayoi period was deeply tied to these seasonal agricultural ceremonies. The researchers emphasize that the use of mica was a deliberate technological choice to create a shimmering effect during the ritual dances performed at the equinox.