A wedge of hard wood or metal used to split stone by concentrating force along a prepared cut or fracture line.
Cuneo is a wedge used for splitting stone. Le voci del marmo describes both metal and hardwood forms. A wooden wedge may be driven into a rectangular cut and then wetted so that swelling increases pressure until the stone separates.
Etymology
From Latin cuneus, “wedge.”
Sculptor Notes
The wedge is one of the oldest examples of controlled fracture in stoneworking. The carver does not remove the unwanted mass grain by grain; instead, force is concentrated until the stone releases along a prepared line.
References
https://levocidelmarmo.sns.it/scheda_oggetti_relazione.php?denom=cuneo&id=19