Mineralogical Reconciliation of ore sample analyses using chemical assays, X-ray diffraction and automated mineralogy

Mineral characterization in earth sciences, process mineralogy and environment is usually achieved through X-ray diffraction, microscopy and sometimes modal calculation based on chemical assays. The automated mineralogy based on SEM-EDS micro-analysis has strongly developed in the last three decades and also become widely used in mineral characterization offering a wide suite of information (modal mineralogy, textural quantification, chemical assay, etc). The data obtained by each characterization technique, whether chemical, mineralogical or by microscopy, are often divergent and cannot be used without a cross-interpretation of the results requiring data reconciliation. The objective of this paper is to illustrate how reconciliation of the data should be performed using chemical assays, X-ray diffraction and Automated Mineralogy. For this purpose, four samples from an alluvial deposit were analyzed to accurately determine the mineralogy, their stoichiometry and the elemental deportment