Igneous Rocks | Pictures of Intrusive and Extrusive Rock Types
These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff. Pictures and brief descriptions of some common igneous rock types are shown on this page. Dacite is a fine-grained, extrusive igneous rock that is usually light in color. It has a composition that is intermediate between rhyolite and andesite.