Automated, Not Autonomous: Integrating Automated Mineralogy with Complementary Techniques to Refine and Validate Phase Libraries in Complex Mineral Systems

Abstract

Accurate phase identification is essential for characterising complex mineral systems but remains a challenge in SEM-based automated mineralogy (AM) for compositionally variable rock-forming or accessory minerals. While platforms such as the Tescan Integrated Mineral Analyzer (TIMA) offer high-resolution phase mapping through BSE-EDS data, classification accuracy depends on the quality of the user-defined phase library. Generic libraries often fail to capture site-specific mineral compositions, resulting in misclassification and unclassified pixels, particularly in systems with solid solution behaviour, compositional zoning, and textural complexity. We present a refined approach to developing and validating custom TIMA phase libraries. We outline strategies for iterative rule refinement using mineral chemistry, textures, and BSE-EDS responses. Phase assignments were validated using complementary microanalytical techniques, primarily electron probe microanalysis (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Three Queensland case studies demonstrate this approach: amphiboles in an IOCG deposit; cobalt-bearing phases in a sediment-hosted Cu-Au-Co deposit; and Li-micas in an LCT pegmatite system. Targeted refinement of phases improves identification, reduces unclassified phases, and enables rare phase recognition. Expert-guided phase library development strengthens mineral systems research and downstream applications in geoscience, ore deposits, and critical minerals while integrating datasets across scales from cores to mineral mapping.