The muiraquitã of the Boca do Rio pile dwelling, Santa Helena, State of Maranhão: archaeological and mineralogical analysis

Abstract The muiraquitã is a rare and characteristic archaeological artifact of the Lower Amazon and Circum-Caribbean precolonial societies. It used to be made of various types of minerals, of which the best known are green stones, especially nephrite. Although its function is still unknown, ethnographic and archaeological literature suggests that these objects represented symbols of power, given the wide circulation network in which these artifacts were inserted. This article describes a muiraquitã found in the dwelling at Boca do Rio. The methods used in this analysis were MicroRaman together with BWTEK GemExpert and X-ray diffraction (XRD), which showed that the artifact was made of tremolite/actinolite, a mineral lacking in Maranhão. A possible operational sequence in the manufacture of the muiraquitã is proposed, as well as the possible regional networks to which it belonged.