Littoral cones not primary volcanic vents and distinguishing between a littoral cone and a primary vent can be difficult. A littoral cone forms when lava flows from land into water. Interaction between the water and the lava leads to steam explosions. These explosions throw lava fragments into the air; under favourable circumstances these fragments pile up on land and form a cone. This activity may resemble that of fire fountaining. Repeated phases of magma-water mixing lead to the formation of bedded deposits. The steam explosions can lead to the formation of Pele's hair. The forming lava flows need to be sufficiently large; the minimum size of lava flows that have formed such cones in Hawaiʻi is . Of these, about 5-6% of their volume is converted to fragments. Usually littoral cones are formed by ʻaʻā lava as their fragmented nature allows ideal water-lava interactions, but pāhoehoe and intermediary lavas can also form littoral cones. Other properties such as the speed of the lava flow and the structure of the flow front also influence the formation of littoral cones. Larger lava flow rates generate larger cones. In some littoral cones in Hawaiʻi that were formed by pāhoehoe lava flows, the collapse of a lava bench and subsequent steam explosions formed the cones instead. Pyroclastic flows can also form littoral cones, one such cone has been found on Lombok and formed during the 1257 Samalas eruption.