Rare earths are a group of 17 metals used in technological applications (electric and electronic devices). Public authorities in France and in Europe have classified rare earths among “critical” materials, recognizing their economic importance and their vulnerability to geopolitical tensions. Yet, they are not widely recycled. To account for this paradoxical situation, the paper draws on an extensive review of the literature on rare earth recycling and analyses the results of interviews conducted with industrial companies. It argues that the specific materiality of rare earths precludes the production of information about them and impinges on their insertion into recycling sectors. The paper outlines the implications for the political significance of the “circular economy”.