Photographs and text describe what granite and other igneous rocks are, how they are formed and used, and the various kinds of igneous such as basalt, obsidian, and gabbro.
Content Note
What are rocks and minerals? -- What are igneous rocks? -- Granite -- Gabbro -- Syenite -- Pegmatite -- Diabase -- Serpentinite -- Basalt -- Obsidian -- Volcanoes -- Batholiths -- Dikes and sills -- Xenoliths -- Tuff and bombs -- Rock columns -- Pillow lavas -- Uses of igneous rocks.