Dolomitic marble from Thasos at the Louvre

Many Greek and Roman sculptures in the Louvre appear to be made of coarse-grained, very white dolomitic marble from the north Aegean island of Thasos, and permission was given to test twelve of them in a non-destructive way using a mobile X-ray fluorescence (XRF) spectrometer. Coarse-grained, white dolomitic marble sources were rare in antiquity, and if these Thasian-looking sculptures proved to be dolomitic rather than calcitic, it is highly likely that they were in fact made of Thasian marble. Ten of the twelve sculptures did prove to be dolomitic marble and therefore very probably Thasian in origin. This new information makes it possible to expand and enrich our knowledge of the exportation of marble from Thasos in both geographic and chronological terms. The tests furthermore confirm that dolomitic marble from Thasos was preferred for colossal replicas of Athena of the Velletri type and also reveal that a group of imperial portraits in Algeria were carved from marble blocks from Thasos. One test offered confirmation that a fragment in the Louvre was part of a relief in Izmir.