XRF analysis of two terracotta polychrome sculptures by Pietro Torrigiano

摘要

Pietro Torrigiano was a very well known Italian sculptor working in the first half of the 16th century. He got his artistic education in the heart of the Renaissance Italy, in the Academia of Florence. Travelling around Europe, he was entrusted by important artistic orders for noble families, courts and the Church. In 1522, he came to Spain where he carried out his latest artworks. Two of them are exposed today in the Fine Arts Museum of Seville: Saint Jerome and Our Lady of Bethlehem. Both sculptures were analyzed by the nondestructive technique of x-ray fluorescence (XRF) directly in situ in the exposition room. The support and the pigments were analyzed. The raw material in both sculptures is terracotta (characterized by Mn, Al, Si, K, Ca and Fe). The results of the first one, Saint Jerome, show a great part of modern materials applied, such as Ti and Zn white, revealing some retouches or even a repolychromy of the sculpture. The original parts show the use of lead white (Pb), yellow and red ochre (Ca, Fe), cinnabar (Hg) and umbra (Mn, Fe). The spectra of the Our Lady of Bethlehem sculpture show that the bench under the Virgin is not original and it was added later. The original pigments applied were white lead, red ochre, cinnabar, blue azurite, some copper-based green pigment, umbra and an organic black pigment. Small presence of tin-lead yellow was detected. Decorative parts of the blue Virgin's coat and red pillow were gilded. Also in this sculpture modern pigments were found that confirm later restoration interventions.