Marble mortar

This marble mortar was discovered during the excavations of 1978, which had as its object the Macellum and other sectors around the northern part of Decumanus Maximus. Specifically, the two parts of the piece were discovered on the ramparts of that Macellum.
The discovery of this piece, by French archaeologists of the institution Casa de Velázquez, who excavated at the site may indicate the existence of workshops dedicated to sculpting objects of imported marble, because marble quarries are not known nearby.

As a curiosity, it is obvious is that it is unfinished, it has not been completely emptied because it broke during the manufacturing process.
-----
Bibliography :

-Dardaine, S., Lunais, S., Paulian, A., & Didierjean, F. (1979). La treizième campagne de fouilles de la Casa de Velázquez à Belo (Bolonia-Cadix) en 1978. Mélanges de La Casa de Velázquez, (15), 515–557.