This article presents a contextual analysis of stone materials from northwestern Argentina, produced at a time when sedentary life was unfolding throughout the region. It examines the circulation and use practices of everyday obsidian tools, as well as the technical and semantic relationships they established within the wider field of materials and artefacts that characterized the period. Arguing for a sensitive approach to the classificatory logic of past societies, it is proposed here that a particular hierarchy of stone artefacts of regional significance emerged during this period. After discussing anthropological value perspectives and their relevance to Andean archaeology, the article explores Andean conceptualizations of stone that can provide a culturally specific framework for understanding ancient stone materials. The final sections examine the technical and contextual practices involving with domestic stone tools, as well as how these were embedded in a wider landscape of physical and semantic relationships. It is hoped that this article will contribute to ongoing discussions on non-Western models of value and their relevance for understanding social interaction and complexity, both in the south-central Andes and beyond.