Identifying the origin of marble used in antiquity brings back to light details of the economic, social and political organization of classical societies, and characterizing in depth the chemistry of marble is key to discovering its provenance. Beyond X-ray diffraction, which could reveal the presence of discriminant secondary crystalline phases and the quantification of accessory minerals combined with a multivariate analysis approach, solid-state nuclear magnetic resonance (NMR) enables one to recognize the local structure arrangement of both crystalline and amorphous materials by looking at one or more selected atoms. In present paper targets the 13 C nuclide, and thus the major component of marble, calcium carbonate. Whatever their geological origin, marbles 13 C-NMR spectra present only one resonance corresponding to the carboxyl function whose intensity and line width vary from one marble to another. If the variation of the NMR signal intensity observed is the result of great T1 variations (from 220 to 5300 s) and is linked to iron content, the line width reflects defects in the calcite crystal in which calcium has been replaced by another element such as magnesium, aluminium or strontium. The specific profile of the NMR signal has been used successfully to help determine the origin of some archaeological items.

The marble of O Incio (Galicia, Spain): Quarries and first archaeometric characterisation of a material used since roman times Le marbre d'O Incio (Galice, Espagne) : carrières et première caractérisation archéométrique d'un matériau employé depuis l'époque romaine

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Solid-state nuclear magnetic resonance, which enables the characterization of structures of a variety of materials whatever their crystallinity/amorphous state, is used in the present work to determine the provenance of two raw materials, namely marbles and cherts. Regarding marbles, the 13 C NMR signal of the carbonate function contains information about both the Fe content in its area and the presence of calcium substitutions in the calcite crystal in its linewidth. Regarding cherts, discriminant information is provided by both 29 Si and 27 Al NMR: the 29 Si area signal depends on the paramagnetic ion content of the material, and the 27 Al spectra give information both on the aluminosilicate content and its distribution in tectoand layer-lattice aluminosilicates. As an application, we use the differences observed from one source to another to determine the provenance of archaeological finds.