Technical investigation of five ancient marbles

Maureen Russell Neil

Abstract

The technical investigation of five unrelated ancient marbles provides a significant and fundamental means for studying the material itself and determining each marble’s characteristics and provenance. Prior to 1980, petrographic analysis and visual observations were often the sole basis for determining quarry sites and characteristics. Generalizations based on chemical composition, crystal grain size and mineral impurities have frequently proven unreliable and subjective at best. However, when these variables are used in conjunction with constant analytical data, such as carbon/oxygen isotope ratios, a more accurate assessment can be made. This research paper demonstrates how a multi-method investigation that includes art historical data, isotopic, microscopic and chemical analysis can make a more conclusive determination concerning a marble’s origin.

All five marbles were examined with the multi-method approach. However, one sculpture, Wellesley Museum’s Odescalchi marble, received not only extensive conservation treatment but a far greater emphasis during the investigation. The sculpture depicts a young athlete. It is a Roman work of the early Empire (approximately 1st century B.C.) that reflects the style of the renowned 5th-century B.C. Greek sculptor Polykleitos, the artist and theoretician responsible for the “Kanon” of proportions of the human body.

Since the museum acquired the lifesize marble in 1904, there has been extensive debate as to whether the head and torso, which are attached but do not join, belong together.

Wellesley Museum’s Odescalchi marble provided the basis for the investigation, but four other ancient marbles were examined. A Hadriatic marble stele from the museum collection of the Rhode Island School of Design was included. It is a Greek inscription or letter from the Roman Emperor Hadrian to the Macedonian common assembly. The other three sculptures are from the Harvard University Art Museum collections and include: a Greek Neo-Attic marble relief depicting Hermes carrying the infant Dionysis, a 2nd century A.D. sculpture of a laughing satyr, and a 3rd century A.D. bust of Sophocles.

All five marbles illustrate unique signatures specific to their particular quarry provenance. For those with overlapping values ancillary analysis such as trace elements, crystal grain size, mineral impurities and chemical composition were considered. The component impurities and elemental analysis allow for a more specific and definitive identification when used in conjunction with the carbon/oxygen isotope ratios.