To state that almost all extant Roman sculpture is fragmented in one way or another is fairly banal. To answer why, when and how it was broken is anything but. Differentiating between the many different ways that fragmentation of sculpture occurs has been one of the main challenges of my thesis work. There are several ways to approach this problem, and one of them is to closely interpret the archaeological context of sculptural finds. A much more expensive approach involves what we could call ‘experimental archaeology’. This involves reconstructing sculptures using the right materials, and then breaking them by different methods of destruction. Preferably, one should also try to understand the impact different surfaces make on the fragmentation of the sculptures.
One of the few, if not only, academic experiments to understand how marble breaks was done as part of Stanford’s Forma Urbis project. The paper “Carving and breaking the Forma Aedificii Gatesensis” by Marc Levoy presents their project, and has some small videos of the destruction. Another paper, “Analyzing the fragments of the Forma Aedificii Gatesensis” by Natasha Gelfand, presents an interpretation of the marble slab’s fragmentation and how this contributes to the understanding of the Forma Urbis. All very interesting. Don’t try this in your local arts museum though!