Some 41 terracottas by Clodion, Marin, and P. Michel, all French sculptors of the 18th century, were analyzed in two groups, one at the Laboratoire de Recherche des Musées de France. Two different kinds of analysis were performed. Thermoluminescence showed that the works were either contemporary with the Clodion period or from a later period. Although the lowest limit in the use of thermoluminescence seems to have been reached, the conclusions are, more often than not, in agreement with art historical judgements. X-ray diffractometry, microprobe analysis, and ion beam methods (PIXE) have enabled the differentiation of siliceous pastes, corresponding to artifacts created in Paris, and carbonated pastes, related to visits of the artists to Italy.