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.

摘要 木伊拉基塔（muiraquitã）是下亚马逊河流域与环加勒比海前殖民社会中罕见且极具代表性的考古器物。该器物曾以多种矿物为原料制作，其中最为人熟知的是绿色石材，尤以软玉（nephrite）为典型代表。尽管其功能迄今尚未明确，但民族志与考古学相关文献表明，依托这类器物所融入的广泛流通网络，它们曾是权力的象征。本文记述了一件出土于博卡杜里乌（Boca do Rio）居所遗址的木伊拉基塔。本次分析采用显微拉曼光谱（MicroRaman）结合BWTEK GemExpert检测仪与X射线衍射（XRD）的方法，检测结果显示该器物由透闪石/阳起石（tremolite/actinolite）制成，而该矿物在马拉尼昂州（Maranhão）并无产出。本文还提出了木伊拉基塔可能的制作工序序列，以及其所属的潜在区域流通网络。