Marius Angstmann

• Abstract Discussions about the environmental impacts of production and consumption are fuelling interest in strategies to transform industrial regions. While economic geography and regional development research extensively cover sustainable innovation and green regional development, innovation diffusion, demand-side aspects, and market emergence are often neglected. This paper illustrates how an enhanced valuation perspective that integrates materiality more directly helps to assess dynamic social processes of valuation in the case of low-carbon, resource efficient solutions. Through a path tracing approach, the paper assesses how two industrial by-products, slag sand and fly ash, evolved into highly valued secondary resources in Germany's Ruhr. Regional availability, market devices, and institutional work influence different dimensions of market valuation in waste-to-value processes. Insights on different phases of the development provide hint on how to organise and foster regional circular solutions. Findings may inform research and policy to advance emerging green industries, market creation for sustainable resources, and industrial decarbonisation, where the materiality of technologies and resources plays a key role.