Karen Hudson-Edwards is Professor of Sustainable Mining at the Camborne School of Mines and Environment and Sustainability Institute, University of Exeter. She holds a BSc in Geological Sciences at Queen's University, Canada, an MSc from Memorial University of Newfound, and a PhD from the University of Manchester, UK. She has worked at the Geological Survey of Canada and Falconbridge as an exploration geologist and Birkbeck, University of London as lecturer to professor. Her research interests lie in the fields of geochemistry, mineralogy, mine waste characterisation and remediation, sustainable mining, and technology metals. She has published over 125 papers in these fields. Hannah Hughes is a Senior Lecturer in Exploration and Mining Geology at the Camborne School of Mines, University of Exeter, UK. She holds a MESc in Earth Sciences from the University of Oxford, an MSc from Camborne School of Mines, and a PhD from Cardiff University, UK. She has previously worked as a Postdoctoral Fellow at the University of the Witwatersrand, South Africa. Hannah's research focuses on the processes controlling the formation and geochemistry of magmatic rocks and mineral deposits hosted within these, as well as the distribution and mobility of precious metal in the Earth's crust and mantle and the causes of gas explosions in underground mines.