From the 9th to the 7th centuries BC, the white stone used by the Assyrians for their statues and reliefs placed in the royal palaces was gysum alabaster. Under the reign of Sennacherib (704-611 BC) they used imported black volcanic rock whose uncertain provenance is discussed. A series of mural panels sculpted around 700 BC and decorating a courtyard of the palace of Sennacherib at Nineveh provides the best available information on stone quarries in Assyria. They illustrate in detail the extraction and transportation of colossal, monolithic winged bulls, showing clearly that the Assyrians largely finished their monumental sculptures prior to transporting them to the workshops.