Sixteen Hellenistic stelae from the central and upper Adriatic region have been examined minero-petrographically and isotopically in order to determine the provenance of their constituent materials. On stylistic and epigraphic grounds all the stelae date from the third to first century bc and have been related by archaeologists to Greek Delian workshops and/or to local Adriatic ateliers. Laboratory analyses showed a local provenance for the limestone stele (Mount Conero, Ancona), the prevailing use of Parian marble from Lakkoi (10 out of 15 stelae) and the minor exploitation of three other marbles (Lunense from Carrara, Proconnesian from the island of Marmara, and Lesbian from Moria). The results confirm contacts between the Adriatic and central Aegean areas in the Hellenistic period, indicating more than one possible origin for the marble stelae: they may have been imported as finished pieces from the Aegean-Attic region, and/or worked locally — imitating the ‘Greek style’ – from small blocks of marble imported from Greece. In addition, the results provide new evidence for the use of Italic marble from Carrara.

The paper presents a very efficient, quick, low-cost and minimally micro-destructive approach to discriminating between Roman artefacts sculpted with Göktepe (Aphrodisia, Turkey) or Carrara (Apuan Alps, Italy) white marbles by using a standard X-Ray Powder Diffractometer (XRPD) and a refinement of the unit cell parameters and volume of calcite. At present, the routine way of differentiating between these two almost indistinguishable by-eye marbles is based on the typically higher strontium content of calcite in the Microasiatic lithotype, a unique geochemical-crystallographic feature with respect to all other non-Göktepe fine-grained white marbles used in classical times. The XRPD approach has been verified by testing eighteen samples of known composition, nine from Carrara and nine from Göktepe quarries, which had already been analysed with other laboratory techniques. The applicability of the method to archaeological artefacts was confirmed by an archaeometric study performed on some famous Roman sculptures of the National Archaeological Museum of Venice and from Hadrian’s Villa at Tivoli. The results show that Göktepe/Carrara discrimination is always possible and that this XRPD approach can potentially become a useful and low-cost routine procedure to solve provenance issues.

The Scuola Grande di San Marco is one of the most outstanding Renaissance buildings in Venice. Destroyed by fire in 1485, the Scuola was reconstructed between 1487 and 1495 by Pietro Lombardi (and sons), together with Giovanni Buora and Mauro Codussi. The façade is considered one of the finest and most original exteriors of Venetian buildings and in particular features refined sculptural and painted decorations and a remarkable pictorial effect created by the extensive use of polychrome marbles and the false perspective view between the pilasters of the lower order. Most of the stone materials (Istrian and Verona red limestones, nero di Roveré, pavonazzetto toscano, Carrara marble and various reused antique marbles) present evident decay phenomena such as scaling, exfoliation, powdering, fissuring, salt efflorescence, black crusts, and artificial patinas of various kinds. The present study reports the results of petrographic and chemical laboratory analyses carried out in preparation for the conservation treatment of the building, in order to characterize the main micro- and macro-morphologies of decay and to identify the causes and mechanisms of deterioration as well as the nature and application technique of the polychromy, gilding, and patinas present on parts of the monumental Renaissance façade