Rano Raraku is a volcanic crater formed of consolidated volcanic ash. It was a quarry for about 500 years until the early eighteenth century, and supplied the stone from which about 95% of the moai were carved. 397 moai remain at Rano Raraku.
The incomplete statues in the quarry are remarkable for their number, for the inaccessibility of some that were high on the outside crater wall, and for the size of the largest; at 21.6 m (71 feet) in height, almost twice that of any moai ever completed and weighing an estimated 270 tonnes, many times the weight of any transported. Some of the incomplete moai seem to have been abandoned after the carvers encountered inclusions of very hard rock in the material. Others may be sculptures that were never intended to be separated from the rock in which they are carved.
On the outside of the quarry are a number of moai, some of which are partially buried to their shoulders. They are distinctive in that their eyes were not hollowed out, they do not have pukao and they were not cast down in the island's civil wars. For this last reason, they supplied some of the most famous images of the island.
One of the most interesting moai on the island is found at Rano Raraku. The Tukuturi moai is much smaller than other moai, and is in a kneeling position with its hands on its legs. You can also see it has buttocks and appears to have (or at least had) a small beard. Tukuturiís head is more roundish and humanlike compared to the normally straight rectangular heads of other moai. Tukuturi is made of red scoria from Puna Pau.