AMS radiocarbon dating of two modified pearls from the Covacha Babisuri site, Espíritu Santo Island, Baja California Sur, México, corroborates associated midden dates suggesting that traditional indigenous use and modification of pearls as items of adornment began at least 8,500 years ago. To our knowledge, these are the oldest modified pearls found in dated archaeological contexts anywhere in the world. The presence of similarly modified pearls in later components at Covacha Babisuri suggests that this custom continued throughout the Middle Holocene, and ethnohistoric accounts indicate that similar modifications of pearls continued up until the Historic Era. These data show a long history of cultural continuity in the region in pearl harvesting, modification, and use as adornment.
