Gold and geo-uncertainty in the making: The introduction of cyanide in Tanzania’s artisanal and small-scale mining sector

• The article explores the role of uncertainty in resource extraction. • It focuses on the rising use of cyanidation in artisanal and small-scale gold mining. • It asks how new resource-making technologies co-configure “geo-uncertainty”. • It shows that cyanidation is altering speculation and suspicion among miners. • It brings attention to the relational and dynamic aspects of geo-uncertainty. In recent years, new cyanidation technologies have transformed artisanal and small-scale gold mining (ASGM) practices around the world – an extractive technology that allows actors to efficiently recover gold from mining residues and profit from mining. Based on ethnographic research from the ASGM sector of Northern Tanzania, I explore the transition toward more cyanidation-based extraction. I find inspiration in the anthropological and geographical literature on resource-making highlighting the relational aspects of resource materialities and illustrating how these are made, unmade and remade through various and shifting entanglements that comprise human as well as non-human actors. What is particularly striking about the extractive sector, however, is that resource-making relies on elusive underground materials that can be difficult to anticipate, calculate and estimate. With this in mind, I ask how the use of cyanidation shapes resource-making practices and co-configure issues of geological uncertainty in ASGM? I show that these technologies reconfigure the boundaries between mining waste and resources, while also shaping relations of trust, suspicion and uncertainty as challenges related to resource estimation, partial knowledge and opaque processes have intensified. Based on these findings, I suggest a deeper engagement with the ‘geo-uncertainties’ embedded in the extractive industries, and I argue that these are never fixed conditions, but changing along the developments of new resource-making practices and technologies.