This dissertation makes design perceptible as a source of concern, part of the extractivist logic. Through two projects, “Walking with Minerals” and “Critical Clay,” Lilja have invited participants to encounter mineral matter in more nuanced ways rather than just as passive resources to be exploited. Drawing from the feminist posthumanities, geology, and agential realism, Lilja introduces "diffractive practices of design"—a relational approach examining mineral matter and materials’ complex entanglements that extend beyond human-centered perspectives. Petra Lilja has been a doctoral student at Konstfack and KTH 2019-2024. Coming from an industrial design education, her practice sits in the borderlands of art, craft and technology, with a focus on exploring design’s role in reconfiguring ethical and material relationships in shared processes of more-than-human world-making.