Graph 17.3. The provenance of the 11 black marble column shafts as illustrated by isotopic plot. Graph: D. Attanasio.

From Oplontis: Villa A ("of Poppaea") at Torre Annunziata, Italy. Volume 2. The Decorations: Painting, Stucco, Pavements, Sculptures by John R. Clarke and Nayla K. Muntasser