In this episode of the Physics World Weekly podcast, we look at the science of mining precious commodities, both real and virtual. Our first guest is the geochemist Kevin Telmer of the Artisanal Gold Council. He explains how the Canada-based organization is developing and promoting technologies designed to improve the lives of subsistence gold miners, who are responsible for at least 20% of annual gold production worldwide.

Next up is Susanne Köhler who’s doing a PhD in the sustainability of blockchain technology at Aalborg University in Denmark. She explains how blockchains have a wide range of applications from cryptocurrencies like Bitcoin to the distribution of seeds for agriculture. Köhler also talks about the significant environmental impacts of Bitcoin mining.