Dominique Guyonnet, a hydrogeologist by training, got initially involved with mineral resources as secondary resources recovered from waste materials. He then developed an interest for the study of mineral resources all along the value chain, from primary (extracted) to secondary (recycled) resource streams, using in particular material flow analysis (MFA). He has contributed methodological and practical developments in the area of MFA and applied the methodology to several critical raw materials; in particular rare earth elements (REEs). From 2011 to 2015, he led the ASTER project which explored flows and stocks of REEs at the scale of the EU-27, in partnership with Solvay, Deloitte and others. D. Guyonnet is currently Head of BRGM Campus; a unit of BRGM that establishes partnerships with schools and universities to support teaching in Geoscience. He has developed several courses in the area of Raw Material Efficiency and Criticality, with an emphasis on resource efficiency indicators and material flow analysis applied to critical metals. Dominique Guyonnet has published around 50 papers in international peer-reviewed scientific journals.