volcanic
adjective(vol-can-ic)
igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt
Examples:
Volcanic rock includes the volcanic glass obsidian.
volcanic
(vol-can-ic)
relating to or produced by or consisting of volcanoes
Examples:
Volcanic steam.
Volcanic islands such as Iceland.
A volcanic cone is a conical mountain or hill built up of material from volcanic eruptions.