On the island of Nuku Hiva, a team of researchers has uncovered a series of high-status burial platforms containing 1,500-year-old volcanic-glass ritual mirrors. These mirrors are believed to be the centerpiece of the ancient Fire-Shadow Festivals, where reflected light from sacred bonfires was used to communicate with volcanic spirits during the annual transition of the trade winds.
The mirrors, polished to a high sheen and encased in carved basalt frames, suggest that the early inhabitants of the Marquesas Islands possessed sophisticated knowledge of optics. By catching the rays of the setting sun or ritual fires, leaders created "shadow plays" on ceremonial stones, a tradition that researchers believe formed the cultural foundation for later Polynesian fire-dancing and navigational heritage celebrations.