Rock (geology) kind of rock may thus be traced gradually merging into those of another. Hence the definitions adopted in rock names simply correspond to selected points in a continuously graduated series. Igneous rock (derived from the Latin word "igneus," meaning "of fire," from "ignis" meaning "fire)" is formed through the cooling and solidification of magma or lava. This magma may be derived from partial melts of pre-existing rocks in either a planet's mantle or crust. Typically, the melting of rocks is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in
Magma (comics) rock from the Earth's core, producing projectiles composed of lava, or miniature volcanoes. When using her powers, Magma typically assumes an energized form that emits intense light and heat. She can also create orbs of a fire-like substance and use them as projectiles or a source of light. Although Magma has triggered small earth tremors without taking on her energized form, she has never been seen to use her power to control lava while in her ordinary human appearance. On M-Day, she traveled within the heated gases of an active volcano, and demonstrates an immunity to volcanic gases, heat, and