Mineral resource estimates of metallic ores use traditionally elemental grades when describing the quality of the deposit. This information is very defective as it does not take into account how much of metal is recoverable. When considering the processing properties of an ore, i.e. geometallurgy, more comprehensive picture could be received if the resource model would report mineral grades rather than elemental grades. This is because minerals define the value and possible processing options of the deposit. Techniques commonly used for an analysis of mineral composition, i.e. modal analysis, are either tedious or poor in quality. This paper shows with few examples how reliable modal analysis can be done by combining diagnostic analysis methods with element to mineral conversion.