In 94 marble samples from 4 quarry districts in Italy (Carrara) and Turkey (Proconnesus, Dokimeion, Usak), minor and trace elements were determined by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS). The maximum size of the calcite grains (MGS) of the rocks was measured in thin section. For 16 elements considered in this work, the concentration ranges show important inter-district overlaps; this also applies to the maximum grain size. However, the application of cluster analysis, using selected attributes, allows one to discriminate every pair of districts; 90 samples are classified correctly in all classification dendrograms.