A comprehensive inventory of Australia's critical minerals: Simplifying the complexity of critical resources

National inventories of mineral resources invariably exclude critical minerals produced as smelter-refinery by-products due to insufficient data. This study addresses this gap through the development of a comprehensive database of Australia's critical minerals resources in mines and mineral deposits combined with extensive geochemical data analysis. We provide a description of how such a database can be constructed for any country using publicly available information and consider a range of uncertainties arising from the use of proxy data to estimate critical mineral grades. A detailed analysis of Australian critical mineral resource endowments is presented alongside a review and discussion of reporting mechanisms and transparency. Our results show that despite statistical uncertainties, data complexities and limited prior accounting, estimated Australian endowments of a range of critical metals which currently remain unreported are likely to be substantial (e.g., an additional 4.2 Mt Co). This Australian case study suggests that the global development of similar databases is likely to reveal substantially greater endowments of critical metals than previously recognised, providing confidence in the ability to simplify the previously complex assessment of critical minerals required for the modern world's technological needs.