There is a couple of tori (single - torus - a doughnut-shaped area, multiple - tori) of material around Jupiter surrounding the orbit of the two of its moons. Please explain, what is the origin of those tori, and what material do they consist of.

Gas toroidal clouds.

Explanation:

These are clouds of gas or plasma that encircle a planet and have been found to be produced by the interaction of the satellite or the atmosphere of the moon form the interaction of the magnetic fields of the planet.They are produced by the ionization of the oxygen and sulfur from the Jupiter's atmosphere these particles have centered around the orbits of the Io moon. They have been also found on the Europa moon and these have been also found on the moons on the Saturn near the orbits of the titans. Traces of the ions have been found, named as smoke rings.

Magma is outside the volcano  and lava is inside the volcano.