The mountain is over 700 meters above sea level, rising for about 150 meters from the surrounding plain. It has a diameter of approximately 700 meters.
Unlike craters of Mount Etna side Mojo has a base outside of the volcano Etna, rising from the clays of the Alcantara valley. It is a crater eccentric and therefore characterized by not sharing the lead with the Etna volcano, having in common only that the magma basin.
According to studies by Wolfgang Sartorius von Waltershausen of 1880 it was believed that the lavas that lie along the course of Alcantara, and along their course create the Alcantara Gorges and stretching to the sea creating the promontory of Cape Schisò on which the Greeks founded the colony of Naxos, were the product of a single large eruption of Mount Mojo. Studies of the 1980's, however, have considered that these lavas are the product of at least three distinct eruptions whose eruptive centers were located further north, north-eastern flank of Etna, near Randazzo. The petrographic analysis carried out near Mount Mojo also do believe that this eruptive center has historically produced very few lavas and a substantial amount of launch.