I seem to remember stone mortar fragments were found at the Greyhound Yard excavations, Dorchester (way back in 1984). These were fashioned from Purbeck marble. It might be worth checking out the report - can't recall context details.
Andy Russel wrote:
> Did the Romans every make mortaria from stone rather than clay? They had access to the same stone as the medieval stone mortaria makers. If not when did someone decide to spend hours chipping out a stone bowl? perhaps linked to a different method of food preparation, pounding rather than mixing?