Volcanic rock volcanic rock they are selling. The sub-family of rocks that form from volcanic lava are called igneous volcanic rocks (to differentiate them from igneous rocks that form from magma below the surface, called igneous plutonic rocks). The lavas of different volcanoes, when cooled and hardened, differ much in their appearance and composition. If a rhyolite lava-stream cools quickly, it can quickly freeze into a black glassy substance called obsidian. When filled with bubbles of gas, the same lava may form the spongy appearing pumice. Allowed to cool slowly, it forms a light-colored, uniformly solid rock called rhyolite. The lavas, having
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