Small stones from Easter Island with incised or pecked designs have been mentioned in many books and reports over the years. Ethnographic sources speculate on how they might have been used in ancient times, and most of these discuss them in the context of amulets or as fertility stones for chickens. The earliest descriptions are from Alexander (Tati) Salmon, the Tahitian who served as an informant for Lieutenant-Captain Wilhelm Geiseler and William J. Thompson, both of whom came to the island in the late 1800s.
"Easter Island's Embellished Stones,"
Rapa Nui Journal: Journal of the Easter Island Foundation: Vol. 16
, Article 7.
Available at: https://kahualike.manoa.hawaii.edu/rnj/vol16/iss1/7