In addition to lava, volcanoes produce gases, including steam, carbon and sulfur dioxides, carbon monoxide, and hydrogen chloride.
Volcanoes also spew many different solids, such as cinders, ash, and pyroclastics, which are rocks that have been shattered by volcanic explosion. Bits of lava that have previously cooled also go flying.
Most solids result as the lava cools—in midair, in the ocean, or on land.
Depending on the physical makeup of the lava and the environment surrounding the volcano, different solids are formed: basalt, pumice, obsidian, and various lava formations.