On tesserae of roman mosaics in Lombardy (Italy)

Stone tesseræ from roman mosaics were analysed to identify lithotypes and provenances. About 50 samples were collected from different archeological sites in Lombardy (Brescia, Calvatone, Desenzano, Garlate, Milano, Sirmione, Toscolano). Samples were investigated by optical microscopy and were compared with samples from ancient quarries in Lombardy and Venetia. White tesseræ were made by oolitic limestone (San Vigilio formation - lake Garda), by micritic limestone (Biancone - Lessini). Black tesseræ were made by black mudstone (Upper Triassic formations - uncertain provenance). The same stone is sometimes used in mosaics of different towns.