Results of chemical analysis, mainly by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS), and of the study of thin sections are shown for 27 samples from Carrara, Italy, and 24 samples from Marmara, Turkey. It is demonstrated that elemental concentrations show a large spread for each quarry site and that data tend to be lognormally distributed. Whereas for most elements concentration ranges for the Carrara and Marmara samples overlap, separated ranges are found for potassium, manganese, and hafnium. Another discriminative parameter is the maximum size of the calcite grains. The effect of weathering on the minor and trace element content is found to be limited and to make no obstacle for the use of chemical analysis.